apprently participating 95% kills isnt good enough to get even a A+ on aram
i went 8/2/50 as sona on aram my only deaths being at the very begining and very end and my team got 61 kills in total (so 58/61). i got a A-
i dont know what riot expects from me but this seems basicly impossible to get even a S- as a support on aram
http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2259628474/226393151?tab=overview ^game im refering to