Frequencies for first 10,000 rows of drugres3 variable in person dataset :

  DRUG TEST |
  RESULTS-3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,933       99.33       99.33
        155 |          1        0.01       99.34
        177 |          1        0.01       99.35
        300 |          1        0.01       99.36
        304 |          2        0.02       99.38
        321 |          2        0.02       99.40
        323 |          1        0.01       99.41
        343 |          4        0.04       99.45
        351 |          4        0.04       99.49
        401 |          1        0.01       99.50
        407 |          4        0.04       99.54
        409 |          1        0.01       99.55
        410 |          2        0.02       99.57
        417 |          2        0.02       99.59
        600 |          5        0.05       99.64
        603 |          2        0.02       99.66
        606 |          2        0.02       99.68
        695 |          2        0.02       99.70
        795 |          1        0.01       99.71
        996 |         18        0.18       99.89
        999 |         11        0.11      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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