Frequencies for first 10,000 rows of ostate variable in linkpe2009psden dataset :

 Occurrence |
  State U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
         GU |      3,422       34.22       34.22
         PR |      6,578       65.78      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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