Frequencies for first 10,000 rows of op_prol variable in natlterr2010 dataset :

  Prolonged |
  Labor RFP |
607=f_ol_pr |
    olong R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      4,656       46.56       46.56
          N |      4,328       43.28       89.84
          U |        993        9.93       99.77
          Y |         23        0.23      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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