Table:
|  | 2019 | 2018 | 2017 |
| --- | --- | --- | --- |
| Year ended 31 March | £m | £m | £m |
| Revenue | 23,428 | 23,723 | 24,062 |
| Operating costs a | (16,461) | (16,828) | (17,323) |
| Depreciation and amortisation | (3,546) | (3,514) | (3,572) |
| Operating profit | 3,421 | 3,381 | 3,167 |
| Net finance expense | (756) | (764) | (804) |
| Associates and joint ventures | 1 | (1) | (9) |
| Profit before tax | 2,666 | 2,616 | 2,354 |
| Tax | (507) | (584) | (446) |
| Profit for the period | 2,159 | 2,032 | 1,908 |
Paragraphs:
Revenue
Both reported and adjusted revenue fell by 1% as growth in our Consumer business, was more than offset by regulated price reductions in Openreach and declines in our enterprise businesses in particular in fixed voice and also reflecting our strategy to reduce low margin activity such as equipment sales. Excluding the negative impact of £35m from foreign exchange movements, underlying revenue fell 0.9% (2017/18: fell 1%), which exceeds our expectation of down around 2%.
You can find details of revenue by customer-facing unit on pages 40 to 41. Note 6 to the consolidated financial statements shows a full breakdown of reported revenue by all our major product and service categories.
Operating costs
Reported operating costs were down 2% and adjustedb operating costs before depreciation and amortisation were down 1%. This was mainly driven by restructuring related cost savings and lower payments to telecommunications operators driven by Global Services strategy to de-emphasise low margin business, partly offset by higher costs of recruiting and training engineers to support Openreach’s ‘Fibre First’ programme and help deliver improved customer service.
Our cost transformation programme remains on track. c4,000 roles were removed in the year, with the largest elements being in Global Services and our Corporate Units. Overall savings from the programme are currently an annualised benefit of £875m with an associated cost of £386m. Note 7 to the consolidated financial statements shows a detailed breakdown of our operating costs.
Note 7 to the consolidated financial statements shows a detailed breakdown of our operating costs.
a Excluding depreciation and amortisation.
Question:
What is the average Depreciation and amortisation for 2017-2019?
Answer: -(3546 + 3514 + 3572) / 3 = -3544