Frequencies for first 10,000 rows of nprev12 variable in natl1991 dataset :

  Number of |
   Prenatal |
     Visits |
     Recode |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        158        1.58        1.58
          2 |        154        1.54        3.12
          3 |        300        3.00        6.12
          4 |        670        6.70       12.82
          5 |      1,025       10.25       23.07
          6 |      1,986       19.86       42.93
          7 |      2,703       27.03       69.96
          8 |      1,291       12.91       82.87
          9 |      1,006       10.06       92.93
         10 |        220        2.20       95.13
         11 |        428        4.28       99.41
         12 |         59        0.59      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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