What is the 1998 value if the 2007 value is 8?
CREATE TABLE "performance_indicators_for_nwsc_1998_201" (
  "1998" text,
  "2000" text,
  "2004" text,
  "2007" text,
  "2011" text
);
SELECT "1998" FROM "performance_indicators_for_nwsc_1998_201" WHERE "2007"='8';