What is the GDP at constant prices for a current account balance of 12.8?
create table table_30133_1 (gdp_at_constant_prices__thb_trillions_ varchar, current_account_balance__percent_of_gdp_ varchar, PRIMARY KEY (gdp_at_constant_prices__thb_trillions_))
select gdp_at_constant_prices__thb_trillions_ from table_30133_1 where current_account_balance__percent_of_gdp_ = "12.8"