Frequencies for first 10,000 rows of refothph variable in nhamcsopd2000 dataset : referred to | other | physician/c | linic | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,061 90.61 90.61 1 | 939 9.39 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016