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

       hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        343        3.43        3.43
          1 |        372        3.72        7.15
          2 |        283        2.83        9.98
          3 |        200        2.00       11.98
          4 |        207        2.07       14.05
          5 |        238        2.38       16.43
          6 |        286        2.86       19.29
          7 |        405        4.05       23.34
          8 |        298        2.98       26.32
          9 |        307        3.07       29.39
         10 |        350        3.50       32.89
         11 |        418        4.18       37.07
         12 |        462        4.62       41.69
         13 |        438        4.38       46.07
         14 |        569        5.69       51.76
         15 |        597        5.97       57.73
         16 |        588        5.88       63.61
         17 |        584        5.84       69.45
         18 |        562        5.62       75.07
         19 |        485        4.85       79.92
         20 |        573        5.73       85.65
         21 |        483        4.83       90.48
         22 |        489        4.89       95.37
         23 |        377        3.77       99.14
         24 |          5        0.05       99.19
         99 |         81        0.81      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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