SELECT E.Firstname+' '+E.Lastname AS FullName,
       ISNULL(CONVERT(varchar, CC.ReportSum), '0') + '/' +
       ISNULL(CONVERT(varchar, OC.ReportSum), '0') AS [Stats]
FROM Employees AS E
JOIN (SELECT EmployeeId,  COUNT(1) AS ReportSum
      FROM Reports R
      WHERE  YEAR(OpenDate) = 2016
      GROUP BY EmployeeId) AS OC ON OC.Employeeid = E.Id
LEFT JOIN (SELECT EmployeeId,  COUNT(1) AS ReportSum
           FROM Reports R
           WHERE  YEAR(CloseDate) = 2016
           GROUP BY EmployeeId) AS CC ON CC.Employeeid = E.Id
ORDER BY FullName