CREATE TABLE table_49572 ("Location" TEXT, "Year" FLOAT, "Champion" TEXT, "Runner-up" TEXT, "Score" TEXT)

When was the earliest year that Guillermo Vilas was the runner-up?
SELECT MIN("Year") FROM table_49572 WHERE "Runner-up" = 'guillermo vilas'
SELECT MIN("Year") FROM "table_49572" WHERE "Runner-up" = 'guillermo vilas'