Frequencies for first 10,000 rows of lmpyr variable in natl1983 dataset : Year Last | Normal | Menses | Began | Freq. Percent Cum. ------------+----------------------------------- - | 166 1.66 1.66 2 | 9,761 97.61 99.27 3 | 73 0.73 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 3 Jan 2016