CREATE TABLE "rise_of_managed_care_in_the_us" (
  "year" real,
  "conventional_plans" text,
  "hm_os" text,
  "pp_os" text,
  "pos_plans" text
);

Question: How many years have HMOs been 27% and POS plans 18%?
SQL: SELECT COUNT("year") FROM "rise_of_managed_care_in_the_us" WHERE "hm_os"='27%' AND "pos_plans"='18%';

Question: Which conventional plan has a POS of 13%?
SQL: SELECT "conventional_plans" FROM "rise_of_managed_care_in_the_us" WHERE "pos_plans"='13%';

Question: How many years have a conventional plan of 7%?
SQL: SELECT SUM("year") FROM "rise_of_managed_care_in_the_us" WHERE "conventional_plans"='7%';

Question: Which conventional plan has a POS plan of 21%?
SQL: SELECT "conventional_plans" FROM "rise_of_managed_care_in_the_us" WHERE "pos_plans"='21%';

Question: Which HMO has a conventional plan of 3% in 2005?
SQL: SELECT "hm_os" FROM "rise_of_managed_care_in_the_us" WHERE "conventional_plans"='3%' AND "year"=2005;