Frequencies for first 10,000 rows of exprmt_rsrch_cndctd_sw variable in pos1997 dataset :

experimenta |
 l research |
  conducted |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,980       99.80       99.80
          Y |         20        0.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 17 May 2017