user: Question: Tell me the total number of years for lady cecily waynflete and opera house, kennedy center
Columns: ['Year', 'Play', 'Role', 'Theatre', 'Location']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1940.0, 'Liliom', 'Julie', 'Forty-Fourth Street Theater', 'New York City , New York']
SQL:

assistant: SELECT SUM("Year") FROM "Table" WHERE "Role" = 'lady cecily waynflete' AND "Theatre" = 'opera house, kennedy center';