hg log devtools -r 'date(-180)' --template '{desc|firstline}\n' | awk '{split($0,a,"r=");print tolower(a[2])}' | grep -v "^$" | sort | uniq -c

reviewers.txt

   1  miker
   1 ato for marionette, rs=mossop for rest)
   5 backout
   1 backout a=backout on a closed tree
   1 backout on a closed tree
   1 baku
   1 baku,
   1 baku,bgrins
  86 bgrins
   1 bgrins, jsantell
   1 bgrins,pbrosset
   2 bholley
   2 billm
   1 billm)
   1 birtles
   1 birtles,a=bustage
   1 bkelly
   8 bz
   1 bz,fitzgen
   4 bz,sfink
   1 ckerschb
   1 ckerschb, 
   3 dao
   1 ednapiranha
   2 efaust,fitzgen,ejpbruel
   2 ehsan
   2 ehsan; a=tomcat
  12 ejpbruel
   1 fabrice 
  59 fitzgen
   1 fitzgen, 
   1 fitzgen.
   1 flod
   1 froydnj
   1 gerv
   2 gijs
   2 gijs)
   1 gijs,mconley,jryans,mattn,mossop)
   4 glandium
   2 glandium,ochameau
   2 gps
   1 heycam,bgrins
   2 heycam,pbrosset
   2 honza
  15 janx
   1 janx,ejpbruel
   1 jaws
   3 jdescottes
   2 jimb
   1 jimb,fitzgen
  10 jlong
  22 jlongster
   1 jlongster 
   1 jlongster,khuey
   1 jmaher
   1 jorendorff
   1 jorendorff)
  86 jryans
   1 jryans p=vladan
   1 jryans,mossop
   1 jryans;
  66 jsantell
   1 jsantell dontbuild
   1 jsantell,ntim
   1 jsantell,vporof
   4 jwalker
   1 khuey
   1 linclark
   2 mattn
   2 mccr8
   1 mconley
  13 me
   1 me closed tree
   1 me for bustage fix on closed tree
  12 miker
   6 mossop
  11 mratcliffe
   3 mrbkap
   2 nfitzgerald
   1 njn
   3 ntim
  23 ochameau
   1 ochameau", wrong bug.
   1 ochameau,glandium,pike,bgrins
   1 odvarko
   8 past
   1 past p=ally
  36 pbro
   1 pbro, 
  52 pbrosset
   1 pbrosset)
   1 pbrosset,
   1 roc,bz
   5 sfink
   1 sfink,bz
   2 shu
   1 shu,jimb
   1 shu.
   2 sicking
   2 sicking)
   2 smaug, jsantell
   1 smaug, jsantell, tromey
   1 smaug, jsantell, tromey, ejpbruel
   1 sphink
   1 standard8
   1 terrence
  15 tromey
   1 tromey 
   1 tromey,vporof,jsantell,jimb
   1 ttromey
   2 vp
  28 vporof
   1 vporof a=bustage
   1 vporof,
   1 vporof,fitzgen
   1 vporof,ntim
   1 vporof]
   1 yzen,mak,yoric,gijs,jlongster
   3 zer0

Cleaned-up a bit:

1 ednapiranha
1 linclark
3 honza
3 jdescottes
3 zer0
4 jwalker
5 jimb
6 ntim
16 ejpbruel
16 janx
20 tromey
24 miker
27 ochameau
35 jlongster
37 vporof
68 fitzgen
75 jsantell
90 jryans
91 bgrins
94 pbro