SELECT COUNT("GDP per capita (nominal)") FROM table_17188 WHERE "GDP (nominal)" = '$29.9 billion'
How many countries has a gdp (nominal) of $29.9 billion?
CREATE TABLE table_17188 (
    "Country" text,
    "Population" real,
    "Area (km\u00b2)" real,
    "GDP (nominal)" text,
    "GDP per capita (nominal)" text
)