Frequencies for first 10,000 rows of nprev12 variable in natl1995 dataset :

  Number of |
   Prenatal |
     Visits |
     Recode |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         93        0.93        0.93
          2 |         79        0.79        1.72
          3 |        181        1.81        3.53
          4 |        490        4.90        8.43
          5 |        746        7.46       15.89
          6 |      1,996       19.96       35.85
          7 |      2,343       23.43       59.28
          8 |      1,585       15.85       75.13
          9 |      1,516       15.16       90.29
         10 |        439        4.39       94.68
         11 |        439        4.39       99.07
         12 |         93        0.93      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015