How many foodborne illness investigations were done in 2014?
foodborne illness investigations refer to inspections where type = 'Foodborne Illness Investigation'; investigations in 2014 refers to date between '2014-01-01' and '2014-12-31';
SELECT COUNT(business_id) FROM inspections WHERE STRFTIME('%Y', `date`) = '2014' AND type = 'Foodborne Illness Investigation'