--Zadanie 2.2 NEW
SELECT id.CustomerID, YEAR(OrderDate), COUNT(*) FROM(
		SELECT DISTINCT CustomerID FROM Sales.SalesOrderHeader WHERE YEAR(OrderDate) = 2011
		INTERSECT
		SELECT DISTINCT CustomerID FROM Sales.SalesOrderHeader WHERE YEAR(OrderDate) = 2014
		EXCEPT
		SELECT DISTINCT CustomerID FROM Sales.SalesOrderHeader WHERE YEAR(OrderDate) = 2012 OR YEAR(OrderDate) = 2013) as id
	JOIN Sales.SalesOrderHeader as sh ON (id.CustomerID = sh.CustomerID)
GROUP BY id.CustomerID, YEAR(OrderDate)
ORDER BY id.CustomerID