Frequencies for first 10,000 rows of prdiag2 variable in namcs2012 dataset :

 Is diagnosis $2 probable, questionable |
                           or rule out? |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
                   No diagnosis entered |      4,606       46.06       46.06
Dx is probable, questionable, or ruleou |         50        0.50       46.56
Dx is not probable, questionable, ruleo |      5,344       53.44      100.00
----------------------------------------+-----------------------------------
                                  Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016