Frequencies for msr_end_qtr variable in vwmeasure_dates dataset :

msr_end_qtr |      Freq.     Percent        Cum.
------------+-----------------------------------
     1Q2012 |         46       55.42       55.42
     2Q2011 |         24       28.92       84.34
     3Q2011 |          1        1.20       85.54
     4Q2010 |          6        7.23       92.77
     4Q2011 |          6        7.23      100.00
------------+-----------------------------------
      Total |         83      100.00

by Jean Roth , jroth@nber.org , 16 Nov 2016