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

       hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        262        2.62        2.62
          1 |        349        3.49        6.11
          2 |        294        2.94        9.05
          3 |        169        1.69       10.74
          4 |        182        1.82       12.56
          5 |        325        3.25       15.81
          6 |        313        3.13       18.94
          7 |        366        3.66       22.60
          8 |        269        2.69       25.29
          9 |        281        2.81       28.10
         10 |        325        3.25       31.35
         11 |        431        4.31       35.66
         12 |        362        3.62       39.28
         13 |        448        4.48       43.76
         14 |        611        6.11       49.87
         15 |        623        6.23       56.10
         16 |        664        6.64       62.74
         17 |        520        5.20       67.94
         18 |        627        6.27       74.21
         19 |        538        5.38       79.59
         20 |        588        5.88       85.47
         21 |        534        5.34       90.81
         22 |        378        3.78       94.59
         23 |        366        3.66       98.25
         24 |          4        0.04       98.29
         99 |        171        1.71      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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