Frequencies for first 10,000 rows of prov2530 variable in pos2007 dataset : spec: | urology | Freq. Percent Cum. ------------+----------------------------------- | 9,666 96.66 96.66 N | 220 2.20 98.86 Y | 114 1.14 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 26 Jan 2016