Frequencies for first 10,000 rows of previs_rec variable in natl2008 dataset :

  Number of |
   Prenatal |
     Visits |
 Recode U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        249        2.49        2.49
          2 |        118        1.18        3.67
          3 |        241        2.41        6.08
          4 |        565        5.65       11.73
          5 |      1,006       10.06       21.79
          6 |      2,093       20.93       42.72
          7 |      2,964       29.64       72.36
          8 |      1,579       15.79       88.15
          9 |        862        8.62       96.77
         10 |        154        1.54       98.31
         11 |        149        1.49       99.80
         12 |         20        0.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 May 2016