Yes, when I give it 1980 as a start year, the spreadsheet covers the 30 years from 1980 to 2009. But when I enter 1983 or 1984, the 30 years are 1982 to 2011, and the data is the same.
So it's really hard to say. Though it does report 113 cycles tested, that seems to match, but I can't count that many lines to know for sure.
I probably have some specific average min/max data from some runs from earlier years - those should show a slight difference, if I copy/pasted it to the dollar. I'll see if I can check those later.
But the spreadsheet would be nice to have.