Maths Based - Stock Turn Analysis - HELP !!!

[CarlCa]

Dear all (especially the Maths wizzs out there)

I am trying to analyse why my shops stock turn is likely to grow over the next few years. The drivers impacting stock turn are:

1) Sales are increasing therefore Cost of Sales (COS) is increasing
2) I am implementing 3 stock reduction plans A, B & C

From the attached you can see stock turn grows each year by 0.5, 0.7 0.9 etc I am trying to explain what proportion of this movement is caused by each of the above driver i.e.

COS 0.1
A 0.2
B 0.1
C 0.1
Total 0.5

But I just cant work out how to do this ... PLEASE HELP

Definition:
Stock turn = (COS / Stock)

Stock Turn Analysis
		Y1	Y2	Y3	Y4	Y5	Y6
Stock		400	350	300	250	200	150
COS		(1,000)	(1,050)	(1,100)	(1,150)	(1,200)	(1,250)
Stock Turn times	2.5	3.0	3.7	4.6	6.0	8.3
Stock Turn YoY Movement		0.5	0.7	0.9	1.4	2.3		Need to explan this YoY growth by below drivers i.e. 1, 2a, 2b and 2c
Stock Turn Drivers
		Y1	Y2	Y3	Y4	Y5	Y6
1)	COS Increasing	(1,000)	(1,050)	(1,100)	(1,150)	(1,200)	(1,250)
	YoY Movement		(50)	(50)	(50)	(50)	(50)
2)	Stock reduction plans
	A	-	10.0	10.0	10.0	10.0	10.0
	B	-	15.0	15.0	15.0	15.0	15.0
	C	-	25.0	25.0	25.0	25.0	25.0
		-	50.0	50.0	50.0	50.0	50.0
2) Cumulative	Stock reduction plans
	A	-	10.0	20.0	30.0	40.0	50.0
	B	-	15.0	30.0	45.0	60.0	75.0
	C	-	25.0	50.0	75.0	100.0	125.0
		-	50.0	100.0	150.0	200.0	250.0

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