Frequencies for first 10,000 rows of drugtst2 variable in person dataset :

  DRUG TEST |
     TYPE-2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,260       92.60       92.60
          1 |        263        2.63       95.23
          2 |         29        0.29       95.52
          3 |         19        0.19       95.71
          7 |          1        0.01       95.72
          8 |          4        0.04       95.76
          9 |        424        4.24      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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