How much diamonds?

Subject:	How much diamonds?
Date:	Thu, 4 Feb 2010 05:38:41 -0800 (PST)

Last time at the club playing teams (IMPs) I faced the following
situation:
I was sitting South, North dealt and we were not vulnerable against
vulnerable opponents. I had this collection:

Q6
92
AKQ9763
75

The bidding went:
N E S
P 1H ?

How many diamonds would you bid? 2, 4, 5?

Reint.