user: Question: Can you tell me the Source that has the Rank of 78?
Columns: ['Name', 'Rank', 'Out of', 'Source', 'Year']
Types: ['text', 'real', 'text', 'text', 'real']
Sample row: ['Environmental Sustainability Index', 132.0, '146', 'Yale University', 2005.0]
SQL:

assistant: SELECT "Source" FROM "Table" WHERE "Rank" = 78.0;