Frequencies for county variable in mmp2014 dataset :

     County |      Freq.     Percent        Cum.
------------+-----------------------------------
      Essex |          1        7.14        7.14
   Franklin |          1        7.14       14.29
    Hampden |          2       14.29       28.57
  Hampshire |          2       14.29       42.86
  Middlesex |          1        7.14       50.00
    Norfolk |          1        7.14       57.14
   Plymouth |          1        7.14       64.29
    Suffolk |          2       14.29       78.57
  Worcester |          3       21.43      100.00
------------+-----------------------------------
      Total |         14      100.00

by Jean Roth , jroth@nber.org , 14 Apr 2016