“that” referring to a preceding phrase
What does “that” mean in the following sentences? Are there any rules which apply to the exact phrases which “that” refers to?
1. The graphs above show the rates of electricity generation of Kansas and “that” of the U.S. total in 2010.
Q. Doesn’t “that” refer to “electricity generation”? If yes, isn’t “of” needed before “that”?
2. The rate of electricity generation by nuclear power plants in Kansas was about the same as that of the U.S. total.
Q. Doesn’t “that” refer to “the rate of electricity generation by nuclear power plants”? If yes, why is it “that in the U.S. total”, instead of “that of the U.S. total” to be parallel with in Kansas?