What was the US national average electric mix rating for the vehicle that was rated 280 g/mi (174 g/km) in the Midwest?
CREATE TABLE table_20553 (
    "Vehicle" text,
    "EPA rated All-electric range" text,
    "EPA rated combined fuel economy" text,
    "Alaska ( Juneau )" text,
    "California (San Francisco)" text,
    "Mid-Atlantic South (Washington, D.C.)" text,
    "U.S. national average electric mix" text,
    "Southeast (Atlanta)" text,
    "Midwest (Des Moines)" text,
    "Rocky Mountains (Denver)" text
)
SELECT "U.S. national average electric mix" FROM table_20553 WHERE "Midwest (Des Moines)" = '280 g/mi (174 g/km)'
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: What was the US national average electric mix rating for the vehicle that was rated 280 g/mi (174 g/km) in the Midwest? ### Input: CREATE TABLE table_20553 (
    "Vehicle" text,
    "EPA rated All-electric range" text,
    "EPA rated combined fuel economy" text,
    "Alaska ( Juneau )" text,
    "California (San Francisco)" text,
    "Mid-Atlantic South (Washington, D.C.)" text,
    "U.S. national average electric mix" text,
    "Southeast (Atlanta)" text,
    "Midwest (Des Moines)" text,
    "Rocky Mountains (Denver)" text
) ### Response: SELECT "U.S. national average electric mix" FROM table_20553 WHERE "Midwest (Des Moines)" = '280 g/mi (174 g/km)'