Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What are all percentages of Left Block when there is a 28.7% Social Democratic?

### Inputs:
table_name: table, columns: ['Date Released', 'Polling institute', 'Socialist', 'Social Democratic', 'Peoples Party', 'Green-Communist', 'Left Bloc', 'Lead']

### Response:
SELECT Left Bloc FROM table WHERE Social Democratic = 28.7%