user: Question: What is the -500 number for Theo Bos?
Columns: ['Rank', 'Race Number', 'Name', 'NOC', '- 250m', '- 500m', '- 750m', '- 1,000m']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 58.0, 'Chris Hoy', 'United Kingdom', '17.984', '31.414', '45.505', '1:00.711']
SQL:

assistant: SELECT "- 500m" FROM "Table" WHERE "Name" = 'Theo Bos';