Frequencies for first 10,000 rows of previs_rec variable in natl2005 dataset :

  Number of |
   Prenatal |
     Visits |
 Recode U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         30        0.30        0.30
          2 |        163        1.63        1.93
          3 |        348        3.48        5.41
          4 |        707        7.07       12.48
          5 |      1,168       11.68       24.16
          6 |      1,946       19.46       43.62
          7 |      2,236       22.36       65.98
          8 |      1,268       12.68       78.66
          9 |        942        9.42       88.08
         10 |        217        2.17       90.25
         11 |        380        3.80       94.05
         12 |        595        5.95      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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