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

       hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        363        3.63        3.63
          1 |        343        3.43        7.06
          2 |        378        3.78       10.84
          3 |        253        2.53       13.37
          4 |        186        1.86       15.23
          5 |        366        3.66       18.89
          6 |        310        3.10       21.99
          7 |        302        3.02       25.01
          8 |        279        2.79       27.80
          9 |        277        2.77       30.57
         10 |        311        3.11       33.68
         11 |        355        3.55       37.23
         12 |        402        4.02       41.25
         13 |        445        4.45       45.70
         14 |        482        4.82       50.52
         15 |        548        5.48       56.00
         16 |        559        5.59       61.59
         17 |        583        5.83       67.42
         18 |        663        6.63       74.05
         19 |        554        5.54       79.59
         20 |        559        5.59       85.18
         21 |        518        5.18       90.36
         22 |        402        4.02       94.38
         23 |        425        4.25       98.63
         99 |        137        1.37      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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