Original Billboard 90’s decade end

[onerandomguy]

Does anyone know what the methodology for the original Billboard 1990’s decade-end chart was? I know it was a point system but was ditched later on and they seem to have orphaned the original 90’s chart.

I’m curious as to what other decade-end charts would look like if it was applied to them, at least the top songs and albums. Or has it not been cracked at all? Any help would be appreciated.