Frequencies for first 10,000 rows of f_mpcb_u variable in linkpe2009psden dataset : Month | Prenatal | Care Began | U | Freq. Percent Cum. ------------+----------------------------------- 0 | 6,582 65.82 65.82 1 | 3,417 34.17 99.99 2 | 1 0.01 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015