Frequencies for first 10,000 rows of prov2290 variable in pos2010 dataset : SPEC: | OPTHAMOLOGY | Freq. Percent Cum. ------------+----------------------------------- | 9,632 96.32 96.32 N | 156 1.56 97.88 Y | 212 2.12 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 26 Jan 2016