Frequencies for pminute variable in parkwork dataset :

 crash time |
   (minute) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         68        5.93        5.93
          1 |         17        1.48        7.42
          2 |         13        1.13        8.55
          3 |         16        1.40        9.95
          4 |          8        0.70       10.65
          5 |         33        2.88       13.53
          6 |         13        1.13       14.66
          7 |         16        1.40       16.06
          8 |         18        1.57       17.63
          9 |         19        1.66       19.28
         10 |         45        3.93       23.21
         11 |         14        1.22       24.43
         12 |          9        0.79       25.22
         13 |         22        1.92       27.14
         14 |          9        0.79       27.92
         15 |         25        2.18       30.10
         16 |         26        2.27       32.37
         17 |         12        1.05       33.42
         18 |         11        0.96       34.38
         19 |         16        1.40       35.78
         20 |         39        3.40       39.18
         21 |         14        1.22       40.40
         22 |          9        0.79       41.19
         23 |         10        0.87       42.06
         24 |         18        1.57       43.63
         25 |         24        2.09       45.72
         26 |         19        1.66       47.38
         27 |         13        1.13       48.52
         28 |         14        1.22       49.74
         29 |         22        1.92       51.66
         30 |         42        3.66       55.32
         31 |         18        1.57       56.89
         32 |         19        1.66       58.55
         33 |          7        0.61       59.16
         34 |          8        0.70       59.86
         35 |         18        1.57       61.43
         36 |         26        2.27       63.70
         37 |         10        0.87       64.57
         38 |         18        1.57       66.14
         39 |         19        1.66       67.80
         40 |         26        2.27       70.07
         41 |         13        1.13       71.20
         42 |         11        0.96       72.16
         43 |         18        1.57       73.73
         44 |         15        1.31       75.04
         45 |         43        3.75       78.80
         46 |          7        0.61       79.41
         47 |         17        1.48       80.89
         48 |         33        2.88       83.77
         49 |         13        1.13       84.90
         50 |         40        3.49       88.39
         51 |          8        0.70       89.09
         52 |         16        1.40       90.49
         53 |         14        1.22       91.71
         54 |         10        0.87       92.58
         55 |         28        2.44       95.03
         56 |         13        1.13       96.16
         57 |         11        0.96       97.12
         58 |         18        1.57       98.69
         59 |         12        1.05       99.74
         99 |          3        0.26      100.00
------------+-----------------------------------
      Total |      1,146      100.00

by Jean Roth , jroth@nber.org , 22 Oct 2016