mines:

SELECT TOP 3 shipcountry, AVG(freight) AS favg FROM Sales.Orders
WHERE YEAR(shippeddate) = 2007
GROUP BY shipcountry
ORDER BY favg DESC

RETURNS:

Austria         186,513
Switzerland 117,1775
Germany         103,1018


a solution from a book:

SELECT TOP(3) shipcountry, AVG(freight) AS avgfreight
FROM Sales.Orders
WHERE orderdate >= '20070101' AND orderdate < '20080101'
GROUP BY shipcountry
ORDER BY avgfreight DESC;

RETURNS:
Austria         178,3642
Switzerland 117,1775
Sweden          99,5122