Summary statistics for stch1995 dataset : by Jean Roth , jroth@nber.org , 17 Oct 2016 Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- agegroup | 954,864 9 5.477228 0 18 racesex | 954,864 4.5 2.291289 1 8 ethnic | 954,864 1.5 .5000003 1 2 pop | 954,864 278.8653 1984.415 0 211785 year | 954,864 1995 0 1995 1995 -------------+--------------------------------------------------------- state | 0 county | 0 by Jean Roth , jroth@nber.org , 17 Oct 2016