Frequencies for first 10,000 rows of nprev28 variable in natl1976 dataset :

  Number of |
   Prenatal |
     Visits |
     Recode |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        122        1.22        1.22
          2 |        164        1.64        2.86
          3 |        187        1.87        4.73
          4 |        279        2.79        7.52
          5 |        440        4.40       11.92
          6 |        468        4.68       16.60
          7 |        600        6.00       22.60
          8 |        580        5.80       28.40
          9 |        767        7.67       36.07
         10 |        703        7.03       43.10
         11 |      1,236       12.36       55.46
         12 |        709        7.09       62.55
         13 |      1,368       13.68       76.23
         14 |        550        5.50       81.73
         15 |        557        5.57       87.30
         16 |        531        5.31       92.61
         17 |        205        2.05       94.66
         18 |         87        0.87       95.53
         19 |         75        0.75       96.28
         20 |         22        0.22       96.50
         21 |         82        0.82       97.32
         22 |          8        0.08       97.40
         23 |          7        0.07       97.47
         24 |          5        0.05       97.52
         25 |          5        0.05       97.57
         26 |         11        0.11       97.68
         27 |         20        0.20       97.88
         28 |        212        2.12      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 Jan 2016