Frequencies for first 10,000 rows of nprevis variable in natl2000 dataset :

      Total |
  Number of |
   Prenatal |
     Visits |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        129        1.29        1.29
          1 |         33        0.33        1.62
          2 |         57        0.57        2.19
          3 |         74        0.74        2.93
          4 |         86        0.86        3.79
          5 |        181        1.81        5.60
          6 |        237        2.37        7.97
          7 |        240        2.40       10.37
          8 |        494        4.94       15.31
          9 |        466        4.66       19.97
         10 |      1,367       13.67       33.64
         11 |        656        6.56       40.20
         12 |      1,965       19.65       59.85
         13 |        747        7.47       67.32
         14 |      1,064       10.64       77.96
         15 |        948        9.48       87.44
         16 |        507        5.07       92.51
         17 |        197        1.97       94.48
         18 |        149        1.49       95.97
         19 |         54        0.54       96.51
         20 |        154        1.54       98.05
         21 |         21        0.21       98.26
         22 |         12        0.12       98.38
         23 |         12        0.12       98.50
         24 |          4        0.04       98.54
         25 |         29        0.29       98.83
         26 |          2        0.02       98.85
         27 |          1        0.01       98.86
         28 |          3        0.03       98.89
         29 |          1        0.01       98.90
         30 |         13        0.13       99.03
         35 |          4        0.04       99.07
         38 |          1        0.01       99.08
         40 |          2        0.02       99.10
         49 |          1        0.01       99.11
         99 |         89        0.89      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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