Your definition of late 90's also includes my definition of mid nighties.
Early 91-3 Mid 94-97 Late 98-2000
Pretty sure 1990 was in the nineties, dude.
There is no year 0 on the Gregorian calender so the first decade was years 1 to 10. 1990 was the last year of the 1980's.
lol. Sorry, but you are unequivocally wrong about this. It doesn't matter when 'the first decade' started; the term 'the nineties' explicitly refers to the years that end with a '9x.