PK 6 Carryovers

It seems the only tracks that has decent Pick 6 carryovers anymore is So. Cal tracks. I wonder why that is? Maybe it's the money in So. Cal. Belmont is probably 2nd but they're uysually half of what Hollywood is. Churchill really puzzles me. Most of the time they're carryover is under 10G for one card. I don't get it. I wonder if the 1$ pick 4 has taken money from the pk 6 since it's been introduced. I know for me I like to play the pick6 once in a while but it cost so much to put in a decent ticket. I'd rather put more money into the pick 4.