How much time do the House and Senate members spend meeting with lobbyists and SIGs?

Granted they handed them $3.7 billion in 2008 and you can verify it at opensecrets.org, it shows what each has taken, from whom and how they vote. But with 30.000 lobbyists in Washington it must take up a ton of time. Granted I am sure staff meets with some and then they get word from family members that work for the lobbyists, but still doesn't seem like it leaves much time to "legislate".