What is the average expenditures on R&D for Croatia after 2007?
CREATE TABLE "list" (
  "rank" real,
  "country_region" text,
  "expenditures_on_r_d_billions_of_us_ppp" real,
  "pct_of_gdp_ppp" text,
  "year" real
);
SELECT AVG("expenditures_on_r_d_billions_of_us_ppp") FROM "list" WHERE "country_region"='croatia' AND "year">2007;