user: Question: Can you tell me total number of Silver that has the Republic of latvian ssr, and the Total larger than 6?
Columns: ['Rank', 'Republic', 'Gold', 'Silver', 'Bronze', 'Total']
Types: ['real', 'text', 'real', 'real', 'real', 'real']
Sample row: [1.0, 'Russian SFSR', 60.0, 56.0, 40.0, 156.0]
SQL:

assistant: SELECT SUM("Silver") FROM "Table" WHERE "Republic" = 'latvian ssr' AND "Total" > 6.0;