user: Question: What was the average year that the Nashville Metros Did not qualify for the Playoffs, Did not qualify for the Open Cup, and had the Regular Season 7th, Southeast?
Columns: ['Year', 'Division', 'League', 'Regular Season', 'Playoffs', 'Open Cup']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1991.0, 'N/A', 'SISL', '4th, Southeast', 'Did not qualify', 'Did not enter']
SQL:

assistant: SELECT AVG("Year") FROM "Table" WHERE "Playoffs" = 'Did not qualify' AND "Open Cup" = 'Did not qualify' AND "Regular Season" = '7th, Southeast';