What is the average value for 1970, when the Region is East Europe (7 Economies), and when 2000 has a value greater than 2?
CREATE TABLE "share_of_global_gdp_ppp_pct" (
  "region" text,
  "1950" real,
  "1960" real,
  "1970" real,
  "1980" real,
  "1990" real,
  "2000" real
);
SELECT AVG("1970") FROM "share_of_global_gdp_ppp_pct" WHERE "region"='east europe (7 economies)' AND "2000">2;