How low was the San Juan income?
CREATE TABLE table_18871 (
    "District" text,
    "2010 Population (000)" real,
    "2008 GDP (USD bn) a" text,
    "2008 GDP per capita (USD) a" real,
    "Agri culture b" text,
    "Mining b" text,
    "Manufac turing b" text,
    "Services & cons truction b" text,
    "Exports (USD mn) 2011" real,
    "Median mo. salary (USD) a e" real,
    "Vehicles (per 1000) d" real,
    "Income poverty f" text,
    "Structural poverty g" text
)
SELECT "Income poverty f" FROM table_18871 WHERE "District" = 'San Juan'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: How low was the San Juan income? ### Input: CREATE TABLE table_18871 (
    "District" text,
    "2010 Population (000)" real,
    "2008 GDP (USD bn) a" text,
    "2008 GDP per capita (USD) a" real,
    "Agri culture b" text,
    "Mining b" text,
    "Manufac turing b" text,
    "Services & cons truction b" text,
    "Exports (USD mn) 2011" real,
    "Median mo. salary (USD) a e" real,
    "Vehicles (per 1000) d" real,
    "Income poverty f" text,
    "Structural poverty g" text
) ### Response: SELECT "Income poverty f" FROM table_18871 WHERE "District" = 'San Juan'