Frequencies for pm_harm variable in parkwork dataset :

       Most |
    Harmful |
      Event |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |          8        0.75        0.75
          6 |          1        0.09        0.85
          8 |         20        1.88        2.73
          9 |          1        0.09        2.82
         12 |        700       65.79       68.61
         14 |        261       24.53       93.14
         16 |          3        0.28       93.42
         18 |          7        0.66       94.08
         30 |          3        0.28       94.36
         31 |          1        0.09       94.45
         45 |          2        0.19       94.64
         54 |         49        4.61       99.25
         72 |          1        0.09       99.34
         99 |          7        0.66      100.00
------------+-----------------------------------
      Total |      1,064      100.00

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