I hope this will help you. You just need to complete the rest of the months with Copy-Paste-Replace.

WITH CTE AS(

SELECT TOP 12 DATEADD( mm, (ROW_NUMBER() OVER(ORDER BY(SELECT NULL)) -1) * -1, DATEADD( mm, DATEDIFF( mm, 0, GETDATE()), 0)) period

FROM sys.all_columns

),

Data AS(

SELECT period,

P.SPRSNSLN AS SPRSNSLN,

ISNULL( Cur.MonthlyGP, 0) MonthlyGP,

ISNULL( Cur.MonthlyRev, 0) MonthlyRev,

ISNULL( Cur.MonthlyGP, 0) - ISNULL( Prev.MonthlyGP, 0) AS MonthlyYOYGPDiff,

ROW_NUMBER() OVER( PARTITION BY P.SPRSNSLN ORDER BY period) MonthNo

FROM CTE

CROSS

JOIN (SELECT DISTINCT SPRSNSLN

FROM GPByMonth) P

LEFT

JOIN GPByMonth Cur ON Cur.M = MONTH( period)

AND Cur.Y = YEAR( Period)

AND P.SPRSNSLN = Cur.SPRSNSLN

LEFT

JOIN GPByMonth Prev ON Prev.M = MONTH( period)

AND Prev.Y = YEAR( Period) - 1

AND P.SPRSNSLN = Prev.SPRSNSLN

)

SELECT SPRSNSLN,

MAX( CASE WHEN MonthNo = 1 THEN period END) AS GPDate_CY1,

MAX( CASE WHEN MonthNo = 1 THEN DATEADD( YEAR, -1, period) END) AS GPDate_PY1,

SUM( CASE WHEN MonthNo = 1 THEN MonthlyGP END) AS MonthlyGP_1,

SUM( CASE WHEN MonthNo = 1 THEN MonthlyRev END) AS MonthlyRev_1,

SUM( CASE WHEN MonthNo = 1 THEN MonthlyYOYGPDiff END) AS MonthlyYOYGPDiff_1,

MAX( CASE WHEN MonthNo = 2 THEN period END) AS GPDate_CY2,

MAX( CASE WHEN MonthNo = 2 THEN DATEADD( YEAR, -1, period) END) AS GPDate_PY2,

SUM( CASE WHEN MonthNo = 2 THEN MonthlyGP END) AS MonthlyGP_2,

SUM( CASE WHEN MonthNo = 2 THEN MonthlyRev END) AS MonthlyRev_2,

SUM( CASE WHEN MonthNo = 2 THEN MonthlyYOYGPDiff END) AS MonthlyYOYGPDiff_2,

MAX( CASE WHEN MonthNo = 3 THEN period END) AS GPDate_CY3,

MAX( CASE WHEN MonthNo = 3 THEN DATEADD( YEAR, -1, period) END) AS GPDate_PY3,

SUM( CASE WHEN MonthNo = 3 THEN MonthlyGP END) AS MonthlyGP_3,

SUM( CASE WHEN MonthNo = 3 THEN MonthlyRev END) AS MonthlyRev_3,

SUM( CASE WHEN MonthNo = 3 THEN MonthlyYOYGPDiff END) AS MonthlyYOYGPDiff_3

FROM Data

GROUP BY SPRSNSLN

ORDER BY SPRSNSLN