Frequencies for first 10,000 rows of nprevis variable in natlterr2000 dataset :

      Total |
  Number of |
   Prenatal |
     Visits |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         85        0.85        0.85
          1 |         26        0.26        1.11
          2 |         64        0.64        1.75
          3 |        120        1.20        2.95
          4 |        229        2.29        5.24
          5 |        304        3.04        8.28
          6 |        499        4.99       13.27
          7 |        552        5.52       18.79
          8 |        760        7.60       26.39
          9 |        701        7.01       33.40
         10 |      2,010       20.10       53.50
         11 |        677        6.77       60.27
         12 |      1,549       15.49       75.76
         13 |        501        5.01       80.77
         14 |        547        5.47       86.24
         15 |        702        7.02       93.26
         16 |        211        2.11       95.37
         17 |        113        1.13       96.50
         18 |        118        1.18       97.68
         19 |         53        0.53       98.21
         20 |         99        0.99       99.20
         21 |         18        0.18       99.38
         22 |         12        0.12       99.50
         23 |          6        0.06       99.56
         24 |          5        0.05       99.61
         25 |          7        0.07       99.68
         26 |          3        0.03       99.71
         28 |          1        0.01       99.72
         29 |          1        0.01       99.73
         30 |          8        0.08       99.81
         31 |          1        0.01       99.82
         35 |          1        0.01       99.83
         37 |          1        0.01       99.84
         38 |          1        0.01       99.85
         39 |          4        0.04       99.89
         99 |         11        0.11      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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