Frequencies for first 10,000 rows of nprevis variable in natl1993 dataset :

      Total |
  Number of |
   Prenatal |
     Visits |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         98        0.98        0.98
          1 |         57        0.57        1.55
          2 |         79        0.79        2.34
          3 |        125        1.25        3.59
          4 |        167        1.67        5.26
          5 |        317        3.17        8.43
          6 |        372        3.72       12.15
          7 |        371        3.71       15.86
          8 |        636        6.36       22.22
          9 |        646        6.46       28.68
         10 |      1,347       13.47       42.15
         11 |        721        7.21       49.36
         12 |      1,665       16.65       66.01
         13 |        803        8.03       74.04
         14 |        811        8.11       82.15
         15 |        802        8.02       90.17
         16 |        334        3.34       93.51
         17 |        137        1.37       94.88
         18 |        113        1.13       96.01
         19 |         65        0.65       96.66
         20 |        147        1.47       98.13
         21 |         23        0.23       98.36
         22 |         10        0.10       98.46
         23 |         15        0.15       98.61
         24 |         14        0.14       98.75
         25 |         39        0.39       99.14
         26 |          6        0.06       99.20
         28 |          6        0.06       99.26
         29 |          3        0.03       99.29
         30 |         15        0.15       99.44
         32 |          1        0.01       99.45
         33 |          1        0.01       99.46
         34 |          1        0.01       99.47
         35 |          3        0.03       99.50
         36 |          2        0.02       99.52
         40 |          1        0.01       99.53
         49 |          3        0.03       99.56
         99 |         44        0.44      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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