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

  DRUG TEST |
  RESULTS-3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,904       99.04       99.04
        167 |          2        0.02       99.06
        187 |          1        0.01       99.07
        208 |          1        0.01       99.08
        304 |          2        0.02       99.10
        321 |          2        0.02       99.12
        343 |          2        0.02       99.14
        351 |          2        0.02       99.16
        352 |          1        0.01       99.17
        367 |          3        0.03       99.20
        401 |          2        0.02       99.22
        402 |          2        0.02       99.24
        407 |          3        0.03       99.27
        417 |          1        0.01       99.28
        423 |          1        0.01       99.29
        603 |          5        0.05       99.34
        695 |          2        0.02       99.36
        996 |         12        0.12       99.48
        999 |         52        0.52      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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