Frequencies for first 10,000 rows of rn variable in nhamcsopd1997 dataset : registered | nurse seen | Freq. Percent Cum. ------------+----------------------------------- 0 | 4,001 40.01 40.01 1 | 5,999 59.99 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016