Table: md_income_data
Columns: county
per_capita_income
median_household_income
population
number_of_households

Question: What is the per capital income for Charles county?
SQL: SELECT "per_capita_income" FROM md_income_data WHERE "county" = 'charles'

Question: What is the per capital income for Washington county?
SQL: SELECT "per_capita_income" FROM md_income_data WHERE "county" = 'washington'