Frequencies for first 10,000 rows of mgntc_rsnc_img_srvc_cd variable in pos2005 dataset :

       srv: |
   magnetic |
  resonance |
    imaging |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,731       87.31       87.31
          0 |      1,242       12.42       99.73
          1 |         12        0.12       99.85
          2 |         14        0.14       99.99
          3 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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