I think the person is asking you for the present CPC rates your presently getting on different parking sites. Nothing special for you to do but to provide what's already in your stats at the 2 or 3 parking sites your presently at.
CPC isn't everything. One site could pay you $1/click and another could pay $0.80. If the 2nd provider has a higher click through rate then you'll end up with more money. RPM (revenue per thousand) is really what matters.
Also a factor for some people is the parking providers stand on incoming links to the domain. Some let you do this while others ONLY want search engine or type-in traffic.
If you have the ability to increase quality traffic to some of your important domains with incoming links, then you can further increase your revenue even if the RPM is lower since you can increase traffic.
Making money parking domain s isn't always a "park a forget about it" experience, or it doesn't have to be. It depends on the amount of time you want to put into it!
Carlo