Write SQL query to solve given problem: How many employees came into the Quality Assurance Group in the year 2007?. Keep the solution inside sql tag ```sql [SQL-Query] ```
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'