Frequencies for first 10,000 rows of mddo variable in namcs2002 dataset :

  Type of physician - MD or |
                         DO |      Freq.     Percent        Cum.
----------------------------+-----------------------------------
  M.D. - Doctor of Medicine |      9,188       91.88       91.88
D.O. - Doctor of Osteopathy |        812        8.12      100.00
----------------------------+-----------------------------------
                      Total |     10,000      100.00

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