CREATE TABLE table_71504 ("Member countries" TEXT, "Population" TEXT, "Area  ( km\\u00b2 ) " TEXT, "GDP  ( billion US$ ) " TEXT, "GDP per capita  ( US$ ) " TEXT)

What is the area of the nation with GDP per capita (US$) of 11,929?
SELECT "Area (km\u00b2)" FROM table_71504 WHERE "GDP per capita (US$)" = '11,929'
SELECT "Area (km\u00b2)" FROM "table_71504" WHERE "GDP per capita (US$)" = '11,929'