CREATE TABLE table_80271 ("Year" FLOAT, "Men's singles" TEXT, "Women's singles" TEXT, "Men's doubles" TEXT, "Women's doubles" TEXT, "Mixed doubles" TEXT)

What's the first year that Guo Xin featured in women's singles?
SELECT MIN("Year") FROM table_80271 WHERE "Women's singles" = 'guo xin'
SELECT MIN("Year") FROM "table_80271" WHERE "Women's singles" = 'guo xin'