Frequencies for first 10,000 rows of proc92d variable in nhamcsopd2010 dataset : procedure 9 | - 2 digit | Freq. Percent Cum. ------------+----------------------------------- -9 | 9,999 99.99 99.99 54 | 1 0.01 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016