根据给定的一组员工数据，找出平均薪资最高的部门。直接输出该部门名称。
{"Name": "Tom", "Department": "Sales", "Salary": "50000"},
{"Name": "Jane", "Department": "Marketing", "Salary": "75000"},
{"Name": "John", "Department": "Sales", "Salary": "65000"},
{"Name": "Alice", "Department": "Finance", "Salary": "80000"},
{"Name": "Bob", "Department": "Marketing", "Salary": "70000";}
平均薪资最高的部门是Finance。