Frequencies for first 10,000 rows of nprev12 variable in natl1985 dataset :

  Number of |
   Prenatal |
     Visits |
     Recode |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        158        1.58        1.58
          2 |        257        2.57        4.15
          3 |        447        4.47        8.62
          4 |        779        7.79       16.41
          5 |      1,082       10.82       27.23
          6 |      1,780       17.80       45.03
          7 |      2,555       25.55       70.58
          8 |      1,653       16.53       87.11
          9 |        787        7.87       94.98
         10 |        194        1.94       96.92
         11 |        227        2.27       99.19
         12 |         81        0.81      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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