What's the abbreviation for the country with an inception of 1999 and US$Billion assets of 7.1?
CREATE TABLE "largest_sovereign_wealth_funds" (
  "country" text,
  "abbreviation" text,
  "assets_us_billion" text,
  "inception" text,
  "origin" text
);
SELECT "abbreviation" FROM "largest_sovereign_wealth_funds" WHERE "inception"='1999' AND "assets_us_billion"='7.1';