How do I forecast depreciation over a five year horizon?

The current formula I am using is (Depreciation Current year / PPE, gross Previous year) * PPE, gross current year.

Current year (20X2) depreciation is 2,407

The issues I am having is how to find PPE, gross.

The information provided for PPE is:

	20X2	20X1
Land and Land improvements	213	224
buildings and building and leasehold improvements	5678	6049
Information Technology Equipment	9643	10589
Production, engineering, office, and other equipment	3161	3222
Total - gross	18695	20085
Less: Accumulated depreciation	13361	14390
Total - net	5334	5694

If I can figure out what PPE, gross is for 20X3 - 20X7, I will be able to figure this out.