結果セットの最後の行にあるすべての列の値の合計を取得する方法は?

同じクエリを繰り返すユニオンを作成しますが、グループ化は行いません:

select Title, Jan, Feb, Mar
from (
  select Master_Code as Title, SUM(Jan) as Jan, SUM(Feb) as Feb, SUM(Mar) as Mar
  from dbo.foobar
  WHERE Participating_City = 'foofoo'
  GROUP BY Master_Code ORDER BY Master_Code ASC
) x
union all
select 'Total', SUM(Jan) as Jan, SUM(Feb) as Feb, SUM(Mar) as Mar
from dbo.foobar
WHERE Participating_City = 'foofoo'