Frequencies for first 10,000 rows of nprevis variable in natlterr1994 dataset :

      Total |
  Number of |
   Prenatal |
     Visits |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        138        1.38        1.38
          1 |         22        0.22        1.60
          2 |         80        0.80        2.40
          3 |        163        1.63        4.03
          4 |        284        2.84        6.87
          5 |        405        4.05       10.92
          6 |        679        6.79       17.71
          7 |        648        6.48       24.19
          8 |        964        9.64       33.83
          9 |        657        6.57       40.40
         10 |      2,272       22.72       63.12
         11 |        562        5.62       68.74
         12 |      1,226       12.26       81.00
         13 |        418        4.18       85.18
         14 |        515        5.15       90.33
         15 |        408        4.08       94.41
         16 |        225        2.25       96.66
         17 |         72        0.72       97.38
         18 |         97        0.97       98.35
         19 |         35        0.35       98.70
         20 |         68        0.68       99.38
         21 |         14        0.14       99.52
         22 |         12        0.12       99.64
         23 |          5        0.05       99.69
         24 |          5        0.05       99.74
         25 |          4        0.04       99.78
         26 |          4        0.04       99.82
         28 |          4        0.04       99.86
         29 |          1        0.01       99.87
         31 |          1        0.01       99.88
         32 |          1        0.01       99.89
         99 |         11        0.11      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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