Frequencies for first 10,000 rows of mgntc_rsnc_img_srvc_cd variable in pos2007 dataset :

       srv: |
   magnetic |
  resonance |
    imaging |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,682       86.82       86.82
          0 |      1,196       11.96       98.78
          1 |         67        0.67       99.45
          2 |         48        0.48       99.93
          3 |          7        0.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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