Frequencies for first 10,000 rows of me_pres variable in natl2017 dataset :

      Fetal |
Presentatio |
       n at |
 Delivery 1 |
   Cephalic |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      9,526       95.26       95.26
          2 |        387        3.87       99.13
          3 |         86        0.86       99.99
          9 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 19 Sep 2018