Frequencies for first 10,000 rows of nprev12 variable in natl2001 dataset :

  Number of |
   Prenatal |
     Visits |
     Recode |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        122        1.22        1.22
          2 |        103        1.03        2.25
          3 |        232        2.32        4.57
          4 |        456        4.56        9.13
          5 |        789        7.89       17.02
          6 |      1,881       18.81       35.83
          7 |      2,598       25.98       61.81
          8 |      1,784       17.84       79.65
          9 |      1,381       13.81       93.46
         10 |        353        3.53       96.99
         11 |        277        2.77       99.76
         12 |         24        0.24      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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