Frequencies for first 10,000 rows of mgntc_rsnc_img_srvc_cd variable in pos2009 dataset :

       SRV: |
   MAGNETIC |
  RESONANCE |
    IMAGING |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,638       86.38       86.38
          0 |      1,126       11.26       97.64
          1 |        120        1.20       98.84
          2 |         96        0.96       99.80
          3 |         20        0.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 17 May 2017