Frequencies for first 10,000 rows of rn variable in nhamcsed1999 dataset : registered | nurse seen | Freq. Percent Cum. ------------+----------------------------------- 0 | 1,352 13.52 13.52 1 | 8,648 86.48 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016