Frequencies for first 10,000 rows of nprev12 variable in natl1989 dataset :

  Number of |
   Prenatal |
     Visits |
     Recode |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        165        1.65        1.65
          2 |        150        1.50        3.15
          3 |        314        3.14        6.29
          4 |        604        6.04       12.33
          5 |        955        9.55       21.88
          6 |      1,818       18.18       40.06
          7 |      2,931       29.31       69.37
          8 |      1,484       14.84       84.21
          9 |        868        8.68       92.89
         10 |        223        2.23       95.12
         11 |        266        2.66       97.78
         12 |        222        2.22      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 Jan 2016