Frequencies for first 10,000 rows of physasst variable in nhamcsopd1996 dataset : physician | assistant | seen | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,859 98.59 98.59 1 | 141 1.41 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016