History behind City and County Data in Realist
The county began using computers for the sales and property data in the late 1980's. So the data goes back about 1988 - 1989 in Realist. CoreLogic's initial data load (at the inception of Realist in 2012) included some 1978/79 sales which may have been picked up another way. It's unusual to find sales in Realist from the 70s, but you might come across some. These are probably incomplete and may or may not link to the actual documents. Prior to the sales data being on computers, the counties used history sheets. One can physically go down to the Real Property Tax Office and view these. This is probably true for the neighbor islands too.