How to grab a private float from class using reflection/

I am currently making a minecraft mod, and I need to set my float to a private float of a base class. They hardcode a method and I am basically extending on it, but it uses the PRIVATE float "rendererUpdateCount"

I am trying to set my float "updateCount" to always equal the value of "rendererUpdateCount"

The problem is I can't seem to get the float's value with reflection.

Currently I am trying to do something like this:

Class er = EntityRenderer.class;
Field field = er.getDeclaredField("rendererUpdateCount");

The only problem is it throws "Unhandled exception type NoSuchFieldException" implying said float does not exist.

So how can i do this correctly?