Frequencies for first 10,000 rows of previs_rec variable in natl2003 dataset :

  Number of |
   Prenatal |
     Visits |
 Recode U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         35        0.35        0.35
          2 |        142        1.42        1.77
          3 |        350        3.50        5.27
          4 |        665        6.65       11.92
          5 |        992        9.92       21.84
          6 |      1,831       18.31       40.15
          7 |      2,153       21.53       61.68
          8 |      1,301       13.01       74.69
          9 |        824        8.24       82.93
         10 |        188        1.88       84.81
         11 |        389        3.89       88.70
         12 |      1,130       11.30      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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