Dereke,
There are no hard numbers for the Squamish system as stock assesment runs no programs up here. What I can tell you is based on best guess and experience of what I and other people see when working on the system. For pinks this year, the Mamquam may of had 20 000 fish which is about what the broodyear was 2 years ago. The Cheakamus around 10 000 fish up from the 4 000 2 years ago. Upper squamish tribs about 20 000 pinks. When you add it up it was a a fairly average year. Certainly a far cry from 2 cycles ago.
Chinook this year ( and the last few) are a total disaster. My guess is well under 1000 fish for the watershed. This is based on native catch and spawner escapements ( which there was none). I would walk sections of streams at what is peak spawner time and see no fish, carcasses or redds.
Chum are just starting to arrive but typically between 100 - 300 000 fish. I have seen both more and less over the years so you never know.
Coho the last few years have been very poor. Hopefully better this year but I would not hold my breath. If you truely want to fish coho, go to the Vedder. The Squamish is a best known for the chum any way (at least now).
As Schenley said, we have no idea how badly we have screwed up this system. He is right, this system is just a pitiful reminder of what it once was. And don't even get me going on what has happened to the steelhead.
As general info I hope you find this interesting but it is not gospel.