user: Question: What is the highest Current Branch Opened, when Neighborhood is W. Portland Park?
Columns: ['Branch', 'Address', 'Neighborhood', 'First branch opened', 'Current branch opened']
Types: ['text', 'text', 'text', 'real', 'real']
Sample row: ['Albina Library', '3605 N.E. 15th Avenue', 'Irvington', 1906.0, 1999.0]
SQL:

assistant: SELECT MAX("Current branch opened") FROM "Table" WHERE "Neighborhood" = 'W. Portland Park';