Frequencies for first 10,000 rows of refothph variable in nhamcsopd1995 dataset : refer to | other | physician/c | linic | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,368 93.68 93.68 1 | 632 6.32 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016