Frequencies for hour variable in person dataset :

       hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         43        3.99        3.99
          1 |         56        5.20        9.19
          2 |         66        6.13       15.32
          3 |         43        3.99       19.31
          4 |         54        5.01       24.33
          5 |         42        3.90       28.23
          6 |         37        3.44       31.66
          7 |         22        2.04       33.70
          8 |         18        1.67       35.38
          9 |         27        2.51       37.88
         10 |         18        1.67       39.55
         11 |         35        3.25       42.80
         12 |         37        3.44       46.24
         13 |         38        3.53       49.77
         14 |         10        0.93       50.70
         15 |         56        5.20       55.90
         16 |         28        2.60       58.50
         17 |         38        3.53       62.02
         18 |         48        4.46       66.48
         19 |         71        6.59       73.07
         20 |         79        7.34       80.41
         21 |         72        6.69       87.09
         22 |         69        6.41       93.50
         23 |         66        6.13       99.63
         24 |          4        0.37      100.00
------------+-----------------------------------
      Total |      1,077      100.00

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