What was the total amount of Value ($M), when the Rank was higher than 6, and the % change on year was -27?
CREATE TABLE "2008_rankings" (
  "rank" real,
  "team" text,
  "country" text,
  "value_m" real,
  "debt_as_pctof_value" real,
  "pct_change_on_year" text,
  "revenue_m" real,
  "operating_income_m" real
);
SELECT COUNT("value_m") FROM "2008_rankings" WHERE "rank">6 AND "pct_change_on_year"='-27';