Frequencies for first 10,000 rows of exchsum4 variable in namcs2011 dataset :

  Practice exchanges patient |
    clinic summaries through |
     secure email attachment |      Freq.     Percent        Cum.
-----------------------------+-----------------------------------
              Not applicable |      6,567       65.67       65.67
                          No |      3,086       30.86       96.53
                         Yes |        347        3.47      100.00
-----------------------------+-----------------------------------
                       Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016