Conceptually reason of decrease in RDF height with increase in water content?

Dear all,

I am doing simulation for a polymer/water system. I would like to do RDF and coordination number analysis for this system. I got results like in figure I attached here. I know the trend is correct but I didn’t understand some concepts. As shown in figure, l=5 (lambda) is the lowest water content and l =25 is highest.
why increase in water content lead to decrease in height exactly? I can not understand this behavior.

As we know, in the distance of first minimum of RDF we can obtain coordination number of first hydration level. on the other hand coordination number is Integral of RDF. But in the highest hydration level we have lowest area under RDF plot and we expect lowest CN but CN is the highest. Why?

Thanks alot in advance