user: Question: What is the povery rate of the county with market income per capita of $20,518?
Columns: ['County', 'Population', 'Unemployment Rate', 'Market Income Per Capita', 'Poverty Rate', 'Status']
Types: ['text', 'real', 'text', 'text', 'text', 'text']
Sample row: ['Bibb', 21482.0, '4.1%', '$16,886', '20.6%', 'At-Risk']
SQL:

assistant: SELECT "Poverty Rate" FROM "Table" WHERE "Market Income Per Capita" = '$20,518';