"lift a cap on" and "clear the backlog"

Hello. I was watching a news program on TV and heard two unfamiliar expressions, and need somebody to help me interpreting them. They are "lift a cap on" and "clear the backlog".

The news was about man who was charged for sexually abuse about 10 years ago, and was recently granted a pardon. The news moved on to a discussion about how the number of pardons granted in Canada is increasing.

In the discussion, the increasing number of demands for parol, and the conservatives' lifting a cap on revenues from the fees charged for pardons were said to "clear the backlog that in 2008 and 2009, nearly 40,000 criminals were granted a pardon.

I'm guessing that lifting a cap means something like, elevating the upper limit, and the backlog means a lot of criminals who were waiting to be granted a pardon, but I'm not sure.

please help, and thank you so much in advance.