CREATE TABLE table_2955 ("Vehicle" TEXT, "Operating mode" TEXT, "EPA rated All-electric range" TEXT, "EPA rated combined fuel economy" TEXT, "Clean electric grid California  ( San Francisco ) " TEXT, "U.S. national average electric mix" TEXT, "Dirty electric grid Rocky Mountains  ( Denver ) " TEXT)

What is the epa rated combined fuel economy for the Nissan Leaf?
SELECT "EPA rated combined fuel economy" FROM table_2955 WHERE "Vehicle" = 'Nissan Leaf'
SELECT "EPA rated combined fuel economy" FROM "table_2955" WHERE "Vehicle" = 'Nissan Leaf'