Frequencies for first 10,000 rows of prov2615 variable in pos1993 dataset : calendar | year test | volume | Freq. Percent Cum. ------------+----------------------------------- | 9,465 94.65 94.65 90 | 292 2.92 97.57 91 | 243 2.43 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 26 Jan 2016