"Brazil, a once-great side who have lost their way in recent years, are fighting for their first final since 1982."
-- Ginny Weasley, The Daily Prophet, 4 July 2014 (QWC)
The Quidditch World Cup 1982 tournament featured the Brazilian National Team in the final match (QWC). It is not clear whether the tournament winner that year was Brazil or their unnamed opponent.
"....the nineties and early noughties were generally considered wilderness years for this once great side"
-- The Daily Prophet, 2 July 2014 (QWC)
1982 being the last time they were in the final before the 2014 tournament, their team's fall from dominance therefore dates from then.
Lexicon timeline of Quidditch
Lexicon list of World Quidditch teams
From the Web
WizardingWorld.com (Pottermore) features:
Writing by J K Rowling on Imgur (Daily Prophet coverage of the 2014 Quidditch World Cup, originally from Pottermore):
- History of the Quidditch World Cup
- Quidditch World Cup 1990-2014
- Match reports and articles from the 2014 Quidditch World Cup
Harry Potter Wiki: Quidditch World Cup