Frequencies for first 10,000 rows of nprevis variable in natlterr2001 dataset :

      Total |
  Number of |
   Prenatal |
     Visits |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         94        0.94        0.94
          1 |         12        0.12        1.06
          2 |         69        0.69        1.75
          3 |        107        1.07        2.82
          4 |        155        1.55        4.37
          5 |        304        3.04        7.41
          6 |        446        4.46       11.87
          7 |        540        5.40       17.27
          8 |        802        8.02       25.29
          9 |        740        7.40       32.69
         10 |      1,971       19.71       52.40
         11 |        710        7.10       59.50
         12 |      1,552       15.52       75.02
         13 |        557        5.57       80.59
         14 |        609        6.09       86.68
         15 |        643        6.43       93.11
         16 |        210        2.10       95.21
         17 |        138        1.38       96.59
         18 |        116        1.16       97.75
         19 |         36        0.36       98.11
         20 |        105        1.05       99.16
         21 |         14        0.14       99.30
         22 |         14        0.14       99.44
         23 |          9        0.09       99.53
         24 |          4        0.04       99.57
         25 |         15        0.15       99.72
         26 |          2        0.02       99.74
         28 |          1        0.01       99.75
         29 |          1        0.01       99.76
         30 |          3        0.03       99.79
         36 |          1        0.01       99.80
         37 |          1        0.01       99.81
         38 |          1        0.01       99.82
         39 |          1        0.01       99.83
         40 |          1        0.01       99.84
         41 |          1        0.01       99.85
         42 |          1        0.01       99.86
         99 |         14        0.14      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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