Frequencies for first 10,000 rows of nprev12 variable in natlterr1996 dataset :

  Number of |
   Prenatal |
     Visits |
     Recode |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        104        1.04        1.04
          2 |        117        1.17        2.21
          3 |        413        4.13        6.34
          4 |        923        9.23       15.57
          5 |      1,452       14.52       30.09
          6 |      2,584       25.84       55.93
          7 |      2,185       21.85       77.78
          8 |      1,072       10.72       88.50
          9 |        773        7.73       96.23
         10 |        206        2.06       98.29
         11 |        166        1.66       99.95
         12 |          5        0.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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