2011 Nismo#91

So I flushed out my clutch fluid twice so far, first after I boiled the fluid at my 2nd track day with the stock fluid, I had already switched out the brake fluid to RBF 660 earlier that year. Switched out out the RBF660 never had a problem with boiling the fluid. A year later I got a brake fluid tester to see if I should replace the brake fluid which was about a year old. I tested the brake fluid and it measured about 2% water content. Since it was the same fluid I decided to test the clutch fluid as well which was only 6 months old, it read >4%! So last year I had the brake and clutch fluid flushed and put both RBF600 in. Last night I got the tester out again and it read 1% on the brake fluid and >4% on the clutch fluid.
Why would so much more water be getting into the clutch fluid system? I know CSC maybe failing but then it would have been failing for over a year and almost 10k miles with track days and dragon runs.