Relay on headlamps, need a little input

Anyone have an idea of what kind of power draws the average 9005 and 9006 bulb requires?

This if for my 91 T-Bird. From 89-97, Ford ran power for: hi and low headlamps, parking and corner lamps as well as foglights through the main headlight switch, and then through the mulitfunction switch. This tends to cause burnouts.... I've already repaired 1 wire on the main light switch that runs to the parking lights, now I'm having my headlights short out occaisionally. I'm going to set them up on relays, I'm just wondering if I'll need 1 30amp relay for each bulb, or if I can use 1 30 amp relay for both 9005s and then another for both 9006s. Any input would be great.

They're just stock bulbs, whatever they're normally rated (55 and 70W I think?). Yes the stock wiring is definately inadaquate.

The headlights started to short out last night. I pulled the switch out (which was pretty hot) and left it sitting in the hole for the gauge cluster (where theres actually some airflow) and they stayed normal for the rest of the night. None of the other wires seem damaged around the switch, so I'm hoping if I run relays on em it'll be fine. If not I can always rewire the switch I guess (I really don't want to :P).

I ordered a pack of 30 amp relays so I can take care of this in a day or two ;)