Frequencies for first 10,000 rows of nprevis variable in natl1999 dataset :

      Total |
  Number of |
   Prenatal |
     Visits |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        138        1.38        1.38
          1 |         37        0.37        1.75
          2 |         62        0.62        2.37
          3 |         91        0.91        3.28
          4 |        130        1.30        4.58
          5 |        185        1.85        6.43
          6 |        262        2.62        9.05
          7 |        269        2.69       11.74
          8 |        437        4.37       16.11
          9 |        465        4.65       20.76
         10 |      1,190       11.90       32.66
         11 |        616        6.16       38.82
         12 |      1,850       18.50       57.32
         13 |        654        6.54       63.86
         14 |      1,091       10.91       74.77
         15 |      1,514       15.14       89.91
         16 |        382        3.82       93.73
         17 |        132        1.32       95.05
         18 |        124        1.24       96.29
         19 |         53        0.53       96.82
         20 |        151        1.51       98.33
         21 |         22        0.22       98.55
         22 |         14        0.14       98.69
         23 |         10        0.10       98.79
         24 |         14        0.14       98.93
         25 |         30        0.30       99.23
         26 |          9        0.09       99.32
         27 |          2        0.02       99.34
         28 |          2        0.02       99.36
         30 |         11        0.11       99.47
         31 |          4        0.04       99.51
         32 |          2        0.02       99.53
         34 |          1        0.01       99.54
         35 |          3        0.03       99.57
         40 |          1        0.01       99.58
         49 |          1        0.01       99.59
         99 |         41        0.41      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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