Would it be useful to use initials with trailing digits, and have a legend at the end of (each page of) the report?

Something like:

Date Range                  Level   Consumers
-------------------------- -------  --------------------------
13 Mar 2004 to 23 Mar 2004      7   AB, AT, DA, MS, RI, RR1, RR2
24 Mar 2004 to 31 Mar 2004      6   AB, DA, RC, RI, RR1, SJ
01 Apr 2004 to 15 May 2004      3   Alan Po, Rohan Ito, Sam Jones
16 May 2004 to 31 Dec 2004      5   AP, PS, RC, RI, SJ
---------------------
RR1: Ron Richards
RR2: Renee Rotunda
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And what happens if you have 2 "John J. Smith"s? Do you append their employee numbers?