CREATE TABLE table_22840 ("Rank" FLOAT, "Race Number" FLOAT, "Name" TEXT, "NOC" TEXT, "- 250m" TEXT, "- 500m" TEXT, "- 750m" TEXT, "- 1 , 000m" TEXT)

What is the -500 number for Theo Bos?
SELECT "- 500m" FROM table_22840 WHERE "Name" = 'Theo Bos'
SELECT "- 500m" FROM "table_22840" WHERE "Name" = 'Theo Bos'