How many rail yards are there in the US? How many yard switches/mainline switches are there in the US?

Question

I am looking for the market information on the # of yards and switches in the US. Ideal answer would be:

There are X yards in the US.

There are Y yard switches in the US.

There are Z mainline switches in the US.

Out of the X, x% are freight, out of the Y, y% are freight, and out of the Z, z% are freight.

Back of the envelope numbers would also work great!

Thanks everyone...

Answer 1

Too many to count. Kinda like the number of grains of sand at the beach.