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

       hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        340        3.40        3.40
          1 |        411        4.11        7.51
          2 |        232        2.32        9.83
          3 |        196        1.96       11.79
          4 |        217        2.17       13.96
          5 |        326        3.26       17.22
          6 |        368        3.68       20.90
          7 |        326        3.26       24.16
          8 |        298        2.98       27.14
          9 |        299        2.99       30.13
         10 |        357        3.57       33.70
         11 |        394        3.94       37.64
         12 |        385        3.85       41.49
         13 |        428        4.28       45.77
         14 |        527        5.27       51.04
         15 |        554        5.54       56.58
         16 |        539        5.39       61.97
         17 |        604        6.04       68.01
         18 |        581        5.81       73.82
         19 |        608        6.08       79.90
         20 |        561        5.61       85.51
         21 |        489        4.89       90.40
         22 |        468        4.68       95.08
         23 |        418        4.18       99.26
         24 |          2        0.02       99.28
         99 |         72        0.72      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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