How many employees came into the Quality Assurance Group in the year 2007?
Quality Assurance Group is a group name of department; came in 2007 refers to year(StartDate) = 2007;
SELECT COUNT(T1.BusinessEntityID) FROM EmployeeDepartmentHistory AS T1 INNER JOIN Department AS T2 ON T1.DepartmentID = T2.DepartmentID WHERE T2.GroupName = 'Quality Assurance' AND STRFTIME('%Y', T1.StartDate) = '2007'