Frequencies for first 10,000 rows of prov3520 variable in pos2010 dataset :

 SRV: BLOOD |
ADMIN-ONSIT |
   E-NONRES |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      7,641       76.41       76.41
          N |      2,339       23.39       99.80
          Y |         20        0.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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