CREATE TABLE table_17188 ("Country" CLOB, "Population" FLOAT, "Area  ( km\\u00b2 ) " FLOAT, "GDP  ( nominal ) " CLOB, "GDP per capita  ( nominal ) " CLOB)

How many countries has a gdp (nominal) of $29.9 billion?
SELECT COUNT("GDP per capita (nominal)") FROM table_17188 WHERE "GDP (nominal)" = '$29.9 billion'
SELECT COUNT("GDP per capita (nominal)") FROM "table_17188" WHERE "GDP (nominal)" = '$29.9 billion'