Frequencies for first 10,000 rows of tbo variable in natl2005 dataset :

Total Birth |
  Order U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      3,009       30.09       30.09
          2 |      2,656       26.56       56.65
          3 |      1,778       17.78       74.43
          4 |      1,046       10.46       84.89
          5 |        620        6.20       91.09
          6 |        339        3.39       94.48
          7 |        222        2.22       96.70
          8 |        111        1.11       97.81
          9 |         73        0.73       98.54
         10 |         50        0.50       99.04
         11 |         25        0.25       99.29
         12 |         22        0.22       99.51
         13 |          6        0.06       99.57
         14 |          4        0.04       99.61
         15 |          1        0.01       99.62
         16 |          3        0.03       99.65
         19 |          1        0.01       99.66
         20 |          1        0.01       99.67
         23 |          1        0.01       99.68
         99 |         32        0.32      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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