| 1 | A | B | C | D |
| --- | --- | --- | --- | --- |
| 2 | depreciation rates for select machinery and equipment categories |  |  |  |
| 3 |  | 1985 to 2001 | 2002 to 2010 | 1985 to 2010 |
| 4 |  | rate |  |  |
| 5 | asset description and code |  |  |  |
| 6 | office furniture, furnishing | 0.200 | 0.282 | 0.227 |
| 7 | computers, associated hardware and word processors | 0.385 | 0.479 | 0.431 |
| 8 | non-office furniture, furnishings and fixtures | 0.224 | 0.259 | 0.240 |
| 9 | scientific, professional and medical devices | 0.197 | 0.198 | 0.189 |
| 10 | heating, electrical, plumbing, air conditioning and refrigeration equipment | 0.132 | 0.204 | 0.130 |
| 11 | pollution abatement and control equipment | 0.115 | 0.146 | 0.125 |
| 12 | motors, generators, transformers, turbines, compressors and pumps of all types | 0.117 | 0.106 | 0.103 |
| 13 | heavy construction equipment | 0.149 | 0.155 | 0.157 |
| 14 | tractors of all types and other field equipment | 0.151 | 0.175 | 0.170 |
| 15 | capitalized tooling and other tools | 0.211 | 0.221 | 0.229 |
| 16 | drilling and blasting equipment | 0.168 | 0.128 | 0.156 |
| 17 | automobiles and major replacement parts | 0.295 | 0.287 | 0.279 |
| 18 | buses (all types) and major replacement parts | 0.125 | 0.098 | 0.103 |
| 19 | trucks, vans, truck tractors, truck trailers and major replacement parts | 0.203 | 0.192 | 0.201 |
| 20 | other transportation equipment | 0.177 | 0.171 | 0.162 |
| 21 | computer-assisted processing machinery and equipment | 0.142 | 0.134 | 0.134 |
| 22 | non-computer-assisted processing machinery and equipment | 0.136 | 0.137 | 0.125 |
| 23 | communication and related equipment | 0.188 | 0.222 | 0.201 |
| 24 | safety and security equipment and other machinery and equipment | 0.145 | 0.185 | 0.167 |
| 25 | mean, all assets | 0.195 | 0.256 | 0.218 |
| 26 |  | standard error |  |  |
| 27 | standard error of mean, all assets | 0.004 | 0.008 | 0.003 |

Question: the mean depreciation rate for these selected machinery and equipment categories as a whole, weighted by their chained dollar investment shares, what was the percentage increased from 1985 to 2001?
Answer: 0.195

Question: the mean depreciation rate for these selected machinery and equipment categories as a whole, weighted by their chained dollar investment shares, what was the percentage increased from 2002 to 2010?
Answer: 0.256