Let's count 'em off!
AT05 -
HAPPY ENDING dress
INSPIRE / Surreal / and so on outfit
my name's WOMEN / GAME dress
CAROLS dress
walking proud / Moments dress
About You outfit
HONEY outfit
encore outfit
-8 outfits
AT06:
Born to Be.. outfit
AUDIENCE / evolution golden outfit
STEP you - Ladies Night outfit
alterna outfit
(m)u + is this LOVE? outfit
Pride - rainy day outfit
Red wig Cleopatra outfit
encore outfit
-8 outfits [I count rip - off costumes that have another underneath as one..]
AT07:
evolution + tophat outfit
M greendress
1LOVE shorts+thing
kiss o' kill metal outfit
Secret / part of Me outfit
Rio \ Carnival! outfit
encore outfit
-7 outfits. 
Remember that there were also like 17/16 songs on MY STORY/(miss)understood, while Secret just had like 14..