How can i find the third highest value in a table?

DECLARE @myTable TABLE (aValue INT)

INSERT INTO @myTable (aValue)
VALUES(123)
INSERT INTO @myTable (aValue)
VALUES(456)
INSERT INTO @myTable (aValue)
VALUES(789)
INSERT INTO @myTable (aValue)
VALUES(234)
INSERT INTO @myTable (aValue)
VALUES(567)
INSERT INTO @myTable (aValue)
VALUES(345)
INSERT INTO @myTable (aValue)
VALUES(678)
INSERT INTO @myTable (aValue)
VALUES(999)

--view all records
SELECT ROW_NUMBER() OVER(ORDER BY aValue DESC) AS aPosition, aValue
FROM @myTable

1	999
2	789
3	678
4	567
5	456
6	345
7	234
8	123

--view only the third highest value
SELECT aValue As [ThirdHighestValue]
FROM (
    SELECT ROW_NUMBER() OVER(ORDER BY aValue DESC) AS aPosition, aValue
    FROM @myTable
) AS t1
WHERE t1.aPosition = 3

SELECT a.Salary FROM MyTable a
WHERE 3 = (SELECT COUNT(DISTINCT (b.Salary)) FROM MyTable b WHERE a.Salary <= b.Salary)

SELECT TOP 1 salary
FROM (
SELECT DISTINCT TOP 3 salary
FROM employee
ORDER BY salary DESC) a
ORDER BY salary