As darben has pointed out, any current stats would be compromised due to the difficulty of booking the connection. (It's possible during Daylight Savings Time, but not during Standard Time.) Plus, even when you can book the connection, you have to "self-transfer" (taxi or walk) from the Amtrak station to the Greyhound station, which is surely a turn-off to potential customers. A dedicated Thruway connection would eliminate both of those barriers.

It would be a mistake to judge demand based on the current substandard service.