LAG FUNCTION in SQL Server 2008

Question

I`m writing on SQL Server 2012 in this SQL function

 

;With Quote as
(
    SELECT
        SID, SHEET, Code, Date, Data,
        LAG(Data) OVER(ORDER BY Date) As LastMonthData
    FROM
        RMQ_DATA
    WHERE
        [SHEET] IN ('0', '1')
)
SELECT
    [Quote].[SID], Quote.DATE, Quote.DATA, Quote.SHEET, Quote.CODE,
    CASE
       WHEN ISNULL(LastMonthData, 0) = 0 THEN null
       ELSE (Data-LastMonthData)/LastMonthData
    END As Quote
FROM
    Quote
Left outer Join
    RMQ_SUBCAT on  Quote.CODE =RMQ_SUBCAT.TARGET_CODE
left outer join
    RMQ_CAT on RMQ_SUBCAT.TARGET_SID=RMQ_CAT.SID
where
    RMQ_CAT.ENABLED='Y' and
    Quote.DATE between '2014/01/01' and '2016/12/01'

but on the first line

;With Quote as (
SELECT SID,SHEET,Code, Date, Data,
       LAG(Data) OVER(ORDER BY Date) As LastMonthData
       FROM RMQ_DATA WHERE [SHEET] IN('0','1'))

LAG(Data) I have an error. So I don't know LAG() function how to use in SQL Server 2008.

How can I solve this trouble ?