Frequencies for first 10,000 rows of nprev12 variable in natl1998 dataset :

  Number of |
   Prenatal |
     Visits |
     Recode |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        131        1.31        1.31
          2 |        101        1.01        2.32
          3 |        239        2.39        4.71
          4 |        461        4.61        9.32
          5 |        929        9.29       18.61
          6 |      1,776       17.76       36.37
          7 |      2,333       23.33       59.70
          8 |      1,634       16.34       76.04
          9 |      1,799       17.99       94.03
         10 |        275        2.75       96.78
         11 |        294        2.94       99.72
         12 |         28        0.28      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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