Question: What is the per-capita GDP for the country with an overall GDP of 156.640?
SQL: SELECT "GDP per capita (US$)" FROM "2-1307842-6" WHERE "GDP (billion US$)" = '156.640';

Question: What is the per-capita GDP of the country with an overall GDP of 80.955?
SQL: SELECT "GDP per capita (US$)" FROM "2-1307842-6" WHERE "GDP (billion US$)" = '80.955';

Question: Which country has an area of 871,980 square km?
SQL: SELECT "Member countries" FROM "2-1307842-6" WHERE "Area (km²)" = '871,980';