on my server there was pugs
Vanilla - zg/aq20
Tbc - everything ecept sunwell
worlk everything
cata t11+ firelands, + a very frew to ds
mop - none not a singel pug- only for world bosses now
i blame the raidfinder but i guess the main reason was a super bad expantion ( cata ) and blizzard killing my server by transfering all iltalians off it, doing firelands we had 11k active players on the server now we have 2.5 according to wowprogress.