Assume the following property and equipment footnote was obtained from the Deere & Company's 2016 10-K. Property and Depreciation A summary of property and equipment at October 31 follows: ($ millions) Average Useful Lives (Years) 2016 2015 Equipment Operations Land $79 $75 Buildings and building equipment 25 1,490 1,419 Machinery and equipment 10 2,961 2,870 Dies, patterns, tools, etc 7 1,039 987 All other 5 589 571 Construction in progress 232 156 Total at cost 6,390 6,078 Less accumulated depreciation 4,113 3,966 Total $2,277 $2,112 During 2016, the company reported $636.5 million of depreciation expense (this expense also includes amortization expense relating to computer software that is included with property and equipment). Estimate the percent used up of Deere's depreciable assets.