Frequencies for first 10,000 rows of drugtst1 variable in person dataset :

  DRUG TEST |
     TYPE-1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,935       69.35       69.35
          1 |      1,600       16.00       85.35
          2 |         81        0.81       86.16
          3 |        175        1.75       87.91
          7 |         59        0.59       88.50
          8 |         36        0.36       88.86
          9 |      1,114       11.14      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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