births <- structure(list(f_age = c(31L, 34L, 36L, 41L, 42L, 37L, 35L, 28L, 22L, 36L, 27L, 35L, 25L, 36L, 27L, 24L, 33L, NA, 28L, 25L, 35L, NA, NA, 29L, 24L, 25L, 34L, NA, NA, 28L, 27L, NA, NA, NA, 33L, 27L, NA, 29L, 33L, NA, NA, 29L, 35L, 27L, 33L, 27L, 30L, NA, 21L, NA, 34L, 22L, 35L, 25L, 22L, 22L, 40L, 24L, 42L, 30L, 35L, 39L, 28L, 29L, 28L, 33L, 29L, 19L, NA, 43L, 33L, 27L, 29L, NA, NA, 34L, 26L, 22L, 31L, 39L, NA, 34L, NA, 30L, 30L, 27L, NA, 24L, 34L, 32L, 26L, NA, 26L, 25L, 24L, 35L, 35L, 28L, 34L, 35L, 30L, 26L, 24L, NA, 34L, NA, 26L, NA, 34L, 20L, 21L, 22L, 32L, 37L, 36L, 31L, 20L, 46L, 23L, 28L, 25L, NA, 17L, 27L, 33L, NA, 26L, 37L, 32L, 24L, 17L, 18L, 24L, NA, 20L, 25L, 33L, 23L, 36L, 31L, NA, NA, 47L, NA, 30L, NA, NA, 31L, 33L, 38L), m_age = c(30L, 36L, 35L, 40L, 37L, 28L, 35L, 21L, 20L, 25L, 19L, 34L, 19L, 33L, 27L, 23L, 40L, 23L, 27L, 22L, 31L, 38L, 26L, 30L, 22L, 25L, 33L, 20L, 28L, 26L, 27L, 21L, 24L, 25L, 30L, 25L, 25L, 21L, 30L, 24L, 23L, 26L, 28L, 22L, 25L, 22L, 25L, 23L, 22L, 32L, 34L, 22L, 31L, 26L, 26L, 34L, 40L, 18L, 38L, 28L, 31L, 27L, 18L, 29L, 24L, 35L, 31L, 20L, 19L, 31L, 27L, 21L, 30L, 20L, 16L, 34L, 26L, 22L, 32L, 37L, 37L, 36L, 32L, 24L, 29L, 24L, 23L, 21L, 29L, 25L, 25L, 41L, 23L, 34L, 19L, 31L, 36L, 25L, 31L, 33L, 25L, 20L, 22L, 26L, 27L, 20L, 17L, 18L, 33L, 23L, 16L, 20L, 35L, 35L, 30L, 23L, 20L, 39L, 25L, 21L, 19L, 24L, 20L, 23L, 27L, 18L, 23L, 33L, 24L, 22L, 17L, 15L, 20L, 21L, 17L, 22L, 33L, 21L, 28L, 29L, 23L, 19L, 24L, 35L, 29L, 17L, 37L, 32L, 28L, 37L), weeks = c(39L, 39L, 40L, 40L, 40L, 40L, 28L, 35L, 32L, 40L, 32L, 40L, 41L, 38L, 39L, 38L, 36L, 40L, 33L, 34L, 37L, 32L, 42L, 39L, 40L, 38L, 43L, 39L, 37L, 39L, 39L, 36L, 38L, 38L, 37L, 40L, 39L, 39L, 39L, 39L, 42L, 39L, 38L, 35L, 35L, 39L, 35L, 44L, 40L, 37L, 38L, 39L, 40L, 39L, 39L, 39L, 38L, 37L, 41L, 39L, 40L, 39L, 41L, 44L, 39L, 38L, 36L, 34L, 39L, 41L, 41L, 41L, 39L, 37L, 40L, 37L, 41L, 40L, 38L, 38L, 38L, 38L, 33L, 41L, 39L, 40L, 41L, 41L, 39L, 41L, 40L, 33L, 42L, 41L, 40L, 39L, 38L, 40L, 40L, 40L, 40L, 41L, 39L, 38L, 39L, 40L, 38L, 40L, 39L, 39L, 38L, 38L, 38L, 40L, 39L, 44L, 37L, 38L, 37L, 38L, 40L, 39L, 39L, 43L, 41L, 33L, 38L, 36L, 39L, 42L, 29L, 37L, 41L, 41L, 40L, 39L, 38L, 40L, 39L, 41L, 36L, 39L, 40L, 37L, 38L, 40L, 39L, 37L, 41L, 26L), premature = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 2L, 2L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 2L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L ), .Label = c("full term", "premie"), class = "factor"), visits = c(13L, 5L, 12L, 13L, NA, 12L, 6L, 9L, 5L, 13L, 5L, 15L, 13L, 10L, 11L, 13L, 13L, 10L, 6L, 10L, 12L, 10L, 15L, 10L, 16L, 19L, 13L, 15L, 13L, 15L, 14L, 15L, 16L, 11L, 10L, 11L, 5L, 18L, 9L, 6L, 9L, 14L, 10L, 12L, 15L, 12L, 15L, 4L, 10L, 8L, 11L, 14L, 10L, 12L, 12L, 12L, 13L, 8L, 15L, 13L, 15L, 12L, 10L, 12L, 11L, 10L, 8L, 13L, 11L, 5L, 15L, 8L, 15L, 10L, 4L, 17L, 10L, 13L, 6L, 5L, 3L, 4L, 10L, 12L, 14L, 11L, 14L, 13L, 15L, 13L, 10L, 13L, 14L, 10L, 12L, 15L, 18L, 7L, 14L, 16L, 12L, 16L, 12L, 14L, 16L, 17L, 11L, 12L, 10L, 15L, 15L, 8L, 17L, 16L, 11L, 14L, 12L, 10L, 8L, 12L, 16L, 8L, 16L, 15L, 14L, 7L, 5L, 11L, 8L, 7L, 4L, 12L, 16L, 12L, 17L, 12L, 15L, 15L, 15L, 12L, 2L, 7L, 12L, 10L, 17L, 15L, 5L, 12L, 10L, 5L), gained = c(1L, 35L, 29L, 30L, 10L, 35L, 29L, 15L, 40L, 34L, 32L, 20L, 47L, 20L, 5L, 22L, 23L, 30L, 18L, 20L, 37L, 16L, 30L, 43L, 34L, 13L, 25L, 70L, 35L, 45L, 31L, 10L, 50L, 27L, 57L, 26L, 37L, 13L, 42L, 30L, 22L, 65L, 25L, 30L, 18L, 30L, 40L, 55L, 85L, 30L, 23L, 29L, 45L, 40L, 31L, 57L, 38L, 25L, 35L, 0L, 32L, 58L, 11L, 51L, NA, 20L, 42L, 6L, 48L, 20L, 38L, 26L, 44L, 26L, 12L, 35L, 68L, 0L, 27L, 45L, NA, 25L, 60L, 40L, 30L, 8L, 19L, 40L, 24L, 50L, 25L, 0L, 23L, 35L, 36L, 35L, 37L, 31L, 44L, 30L, 35L, 21L, 32L, 40L, 24L, 39L, 30L, 13L, 40L, 56L, 75L, 45L, 55L, 32L, 21L, 40L, 22L, 35L, 53L, 40L, 37L, 22L, 35L, 30L, 58L, 40L, 28L, 15L, 23L, 21L, 10L, 76L, 35L, 32L, 38L, 27L, 60L, 38L, 40L, 30L, 27L, 0L, 46L, 25L, 55L, 20L, 20L, 22L, 30L, 25L), weight = c(6.8799999999999999, 7.6900000000000004, 8.8800000000000008, 9, 7.9400000000000004, 8.25, 1.6299999999999999, 5.5, 2.6899999999999999, 8.75, 6.5, 7.4400000000000004, 8.3800000000000008, 6, 7.8099999999999996, 7.8099999999999996, 7.8099999999999996, 7.3099999999999996, 4.75, 3.75, 8.0600000000000005, 2.1899999999999999, 7.3799999999999999, 6.8799999999999999, 6.8799999999999999, 7.6299999999999999, 9.1300000000000008, 7.3799999999999999, 8.25, 7.1900000000000004, 7.5599999999999996, 6.8099999999999996, 3.75, 8.75, 6.5599999999999996, 7.4400000000000004, 6, 7.75, 7.8099999999999996, 6.1299999999999999, 8.8100000000000005, 7.75, 6.8799999999999999, 4.6900000000000004, 6.75, 6.9400000000000004, 4.5, 8.1300000000000008, 5.8099999999999996, 6.8099999999999996, 7.25, 7.1900000000000004, 8, 8.3800000000000008, 7.3099999999999996, 9.6899999999999995, 7.3099999999999996, 6.1900000000000004, 10.130000000000001, 7.5, 6.25, 8.5600000000000005, 6.5, 8.5, 7.5, 6.4400000000000004, 5.9400000000000004, 4.5, 8.3800000000000008, 7.0599999999999996, 7, 5.9400000000000004, 6.3799999999999999, 5.3799999999999999, 6, 6.8799999999999999, 9.3100000000000005, 6.5, 6.75, 5.1299999999999999, 7.5, 6.8799999999999999, 5.0599999999999996, 8.1300000000000008, 5.3799999999999999, 7.6900000000000004, 7.8799999999999999, 7.8799999999999999, 8.25, 7.75, 7, 5.6900000000000004, 6.75, 8.1899999999999995, 8.1899999999999995, 7.4400000000000004, 8.25, 9.1899999999999995, 7.5, 6.8099999999999996, 8.1300000000000008, 6.3099999999999996, 8.3800000000000008, 8, 8.8800000000000008, 9.0600000000000005, 9.5, 8.75, 8.0600000000000005, 7.3099999999999996, 7.5599999999999996, 7.4400000000000004, 7.5, 7.3099999999999996, 7.8799999999999999, 6.8099999999999996, 5.9400000000000004, 6.75, 7.6900000000000004, 7.3799999999999999, 7.9400000000000004, 5, 5.6299999999999999, 7.8099999999999996, 8, 1.6899999999999999, 7.1900000000000004, 6.3099999999999996, 6.8799999999999999, 6.5, 2.6299999999999999, 8.4399999999999995, 7.1900000000000004, 8.3800000000000008, 7.1900000000000004, 6.3099999999999996, 6.5599999999999996, 7.6299999999999999, 8.3800000000000008, 7.6900000000000004, 5.8799999999999999, 7.3099999999999996, 6.8799999999999999, 5.6299999999999999, 7, 7.6299999999999999, 8.1899999999999995, 6, 8.1300000000000008, 3.6299999999999999), sex_baby = structure(c(2L, 2L, 2L, 1L, 2L, 2L, 1L, 1L, 2L, 1L, 1L, 2L, 2L, 2L, 2L, 1L, 1L, 2L, 2L, 2L, 1L, 1L, 2L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 2L, 1L, 2L, 2L, 2L, 1L, 1L, 2L, 1L, 2L, 1L, 2L, 2L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 1L, 1L, 2L, 2L, 1L, 2L, 1L, 1L, 2L, 2L, 1L, 1L, 2L, 1L, 2L, 1L, 1L, 1L, 2L, 2L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 2L, 1L, 2L, 2L, 2L, 2L, 1L, 2L, 2L, 1L, 2L, 2L, 2L, 2L, 1L, 2L, 2L, 2L, 1L, 1L, 1L, 1L, 2L, 2L, 1L, 2L, 1L, 2L, 2L, 1L, 1L, 1L, 2L, 2L, 1L, 2L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 1L, 2L, 1L, 2L, 2L, 1L, 2L, 2L, 2L, 1L, 1L, 1L, 1L, 2L, 2L), .Label = c("female", "male"), class = "factor"), smoke = structure(c(2L, 1L, 1L, 1L, 1L, 2L, 1L, 2L, 2L, 1L, 1L, 1L, 2L, 1L, 2L, 1L, 1L, 1L, 2L, 1L, 1L, 2L, 2L, 1L, 2L, 1L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 2L, 2L, 1L, 2L, 1L, 1L, 1L, 2L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 2L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 2L, 2L, 1L, 2L, 2L, 2L, 1L, 2L, 2L, 1L, 1L, 1L, 2L, 1L, 1L, 2L, 2L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 2L, 2L, 2L, 1L, 1L, 1L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 2L, 2L, 1L, 1L, 1L, 2L, 1L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 1L, 2L, 1L, 1L, 1L), .Label = c("nonsmoker", "smoker"), class = "factor")), row.names = c(NA, -150L), class = c("tbl_df", "tbl", "data.frame"))