user: Question: How many red breasted nuthatch coins created before 2007 were minted, on average?
Columns: ['Year', 'Animal', 'Artist', 'Finish', 'Mintage', 'Issue Price']
Types: ['real', 'text', 'text', 'text', 'real', 'text']
Sample row: [2007.0, 'Ruby-Throated Hummingbird', 'Arnold Nogy', 'Specimen (with selective colouring)', 25000.0, '$24.95']
SQL:

assistant: SELECT AVG("Mintage") FROM "Table" WHERE "Animal" = 'red breasted nuthatch' AND "Year" < 2007.0;