Frequencies for first 10,000 rows of ld_ster variable in natlterr2007 dataset :

   Steroids |
        RFP |
611=f_ld_st |
   eroids R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      6,163       61.63       61.63
          N |      3,738       37.38       99.01
          U |          1        0.01       99.02
          Y |         98        0.98      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015