Frequencies for first 10,000 rows of nprev12 variable in natl1992 dataset :

  Number of |
   Prenatal |
     Visits |
     Recode |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        133        1.33        1.33
          2 |        136        1.36        2.69
          3 |        323        3.23        5.92
          4 |        646        6.46       12.38
          5 |      1,041       10.41       22.79
          6 |      1,985       19.85       42.64
          7 |      2,550       25.50       68.14
          8 |      1,464       14.64       82.78
          9 |      1,040       10.40       93.18
         10 |        342        3.42       96.60
         11 |        302        3.02       99.62
         12 |         38        0.38      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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