user: Question: What are all percentages of Left Block when there is a 28.7% Social Democratic?
Columns: ['Date Released', 'Polling institute', 'Socialist', 'Social Democratic', 'Peoples Party', 'Green-Communist', 'Left Bloc', 'Lead']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['February 20, 2005', 'Election Results', '45.0% 121 seats', '28.8% 75 seats', '7.2% 12 seats', '7.5% 14 seats', '6.4% 8 seats', '16.2%']
SQL:

assistant: SELECT "Left Bloc" FROM "Table" WHERE "Social Democratic" = '28.7%';