From what I could gather from reading their manual, from around the 1900s, when that jurisdiction began, it was four days a week. Then they went down to three days a week from 1950 to 1984, and then from 1984 to present they went back up to four days a week.
I don't know about the amount. I know about the amount of time that they currently sit, but I'm afraid I don't know much more about it.