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

  DRUG TEST |
  RESULTS-3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,885       98.85       98.85
          1 |         26        0.26       99.11
        187 |          1        0.01       99.12
        307 |          1        0.01       99.13
        321 |          1        0.01       99.14
        355 |          1        0.01       99.15
        405 |          1        0.01       99.16
        407 |          5        0.05       99.21
        417 |          6        0.06       99.27
        418 |          1        0.01       99.28
        600 |          5        0.05       99.33
        603 |          4        0.04       99.37
        605 |          3        0.03       99.40
        695 |          2        0.02       99.42
        996 |          3        0.03       99.45
        998 |          1        0.01       99.46
        999 |         54        0.54      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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