Frequencies for first 10,000 rows of quarterbegin variable in sdued1991 dataset :

    Quarter |
      Begin |      Freq.     Percent        Cum.
------------+-----------------------------------
        1/1 |      4,252       42.52       42.52
        4/1 |      4,894       48.94       91.46
        7/1 |        854        8.54      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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