Table schema:
CREATE TABLE table_2508175_1 (annual_co2_emissions__in_thousands_of_metric_tons_ INTEGER, gdp_per_emissions__in_us_dollars_per_ton_ VARCHAR)

Question: when the gdp per emissions (in us dollars per ton) is 3903, what is the maximum annual co2 emissions (in thousands of metric tons)?
SQL: SELECT MAX(annual_co2_emissions__in_thousands_of_metric_tons_) FROM table_2508175_1 WHERE gdp_per_emissions__in_us_dollars_per_ton_ = 3903