Frequencies for first 10,000 rows of segmentid variable in maa_to_m2009 dataset :

 Segment ID |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,392       93.92       93.92
          1 |        143        1.43       95.35
          2 |        226        2.26       97.61
          3 |        239        2.39      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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