Frequencies for first 10,000 rows of ume_forcep variable in natlterr2005 dataset :

Forceps U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         12        0.12        0.12
          2 |      8,247       82.47       82.59
          9 |      1,741       17.41      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015