Frequencies for first 10,000 rows of f_op_ruptr variable in linkpe2013usnum dataset :

  Premature |
 Rupture of |
        the |
 Membrane R |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      1,599       15.99       15.99
          1 |      8,209       82.09       98.08
          3 |        192        1.92      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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