Frequencies for first 10,000 rows of hour variable in person dataset :

       hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        356        3.56        3.56
          1 |        267        2.67        6.23
          2 |        259        2.59        8.82
          3 |        168        1.68       10.50
          4 |        183        1.83       12.33
          5 |        275        2.75       15.08
          6 |        303        3.03       18.11
          7 |        327        3.27       21.38
          8 |        339        3.39       24.77
          9 |        246        2.46       27.23
         10 |        345        3.45       30.68
         11 |        405        4.05       34.73
         12 |        423        4.23       38.96
         13 |        534        5.34       44.30
         14 |        521        5.21       49.51
         15 |        664        6.64       56.15
         16 |        659        6.59       62.74
         17 |        625        6.25       68.99
         18 |        698        6.98       75.97
         19 |        538        5.38       81.35
         20 |        505        5.05       86.40
         21 |        472        4.72       91.12
         22 |        428        4.28       95.40
         23 |        398        3.98       99.38
         24 |          5        0.05       99.43
         99 |         57        0.57      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016