Frequencies for first 10,000 rows of quarter variable in sdued1999 dataset :

    Quarter |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      6,451       64.51       64.51
          2 |      3,549       35.49      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Feb 2018