You say you went 5/1/16 as a support?
That is an AMAZING ratio for a support.
Whatever it is you were doing, keep doing it.
Your expected k/d/a depends on what type of champion you are playing.
-Well played AP casters and supports usually get a low number of kills and death, but a lot of assists.
-Well played tanks tend to have a few more deaths and assists, because their job is to be on the front line as a damage soak.
-Carries are expected to have extremely high k/d/a's, as their role is to dish out damage and stay alive as long as possible.
Well, as long as you win, k/d/a doesn't really matter.
Kills are merely a means to an end in Dominion.