Frequencies for first 10,000 rows of nprev12 variable in natl1994 dataset :

  Number of |
   Prenatal |
     Visits |
     Recode |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        110        1.10        1.10
          2 |        101        1.01        2.11
          3 |        224        2.24        4.35
          4 |        499        4.99        9.34
          5 |        758        7.58       16.92
          6 |      2,287       22.87       39.79
          7 |      2,421       24.21       64.00
          8 |      1,628       16.28       80.28
          9 |      1,182       11.82       92.10
         10 |        308        3.08       95.18
         11 |        356        3.56       98.74
         12 |        126        1.26      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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