user: Question: What is the total for Canada during round 2?
Columns: ['Round', 'Overall', 'Player', 'Position', 'Nationality', 'Club team']
Types: ['real', 'real', 'text', 'text', 'text', 'text']
Sample row: [1.0, 15.0, 'Erik Karlsson', 'Defence', 'Sweden', 'Frölunda HC (Gothenburg) (Sweden)']
SQL:

assistant: SELECT SUM("Overall") FROM "Table" WHERE "Nationality" = 'Canada' AND "Round" = 2.0;