Frequencies for first 10,000 rows of nprev12 variable in natl2002 dataset :

  Number of |
   Prenatal |
     Visits |
     Recode |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         44        0.44        0.44
          2 |        181        1.81        2.25
          3 |        345        3.45        5.70
          4 |        674        6.74       12.44
          5 |        981        9.81       22.25
          6 |      2,042       20.42       42.67
          7 |      2,129       21.29       63.96
          8 |      1,310       13.10       77.06
          9 |        933        9.33       86.39
         10 |        195        1.95       88.34
         11 |        359        3.59       91.93
         12 |        807        8.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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