user: Question: What is the GDP at constant prices for a current account balance of 12.8?
Columns: ['Year', 'GDP at constant prices (THB trillions)', 'GDP at constant prices growth rate (percent change)', 'GDP at current prices (USD billions)', 'Export volume of goods and services (percent change)', 'Current account balance (percent of GDP)']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1995.0, '2.941', '9.2', '168.019', '15.4', '-7.9']
SQL:

assistant: SELECT "GDP at constant prices (THB trillions)" FROM "Table" WHERE "Current account balance (percent of GDP)" = '12.8';