Table:
|  | 2019 | 2018 | 2017 |
| --- | --- | --- | --- |
| Year ended 31 March | £m | £m | £m |
| Cash generated from operations | 4,687 | 5,400 | 6,725 |
| Tax paid | (431) | (473) | (551) |
| Net cash inflows from operating activities | 4,256 | 4,927 | 6,174 |
| Net purchase of property, plant and equipment and software | (3,637) | (3,341) | (3,119) |
| Free cash flow | 619 | 1,586 | 3,055 |
| Interest received | 23 | 7 | 7 |
| Interest paid | (531) | (555) | (629) |
| Add back pension deficit payments | 2,024 | 872 | 274 |
| Add back net cash flow from specific items | 598 | 828 | 205 |
| Add back net sale of non-current asset investments | 1 | 19 | (20) |
| Add back prepayments in respect of acquisition of spectrum licence | - | 325 | - |
| Remove refund on acquisition of spectrum licence | (21) | - | - |
| Remove cash tax benefit of pension deficit payments | (273) | (109) | (110) |
| Normalised free cash flow b | 2,440 | 2,973 | 2,782 |
Paragraphs:
Summarised cash flow statement
Cash flow
We generated a net cash inflow from operating activities of £4,256m, down £671m, mainly driven by £2bn contributions to the BT Pension Scheme, offset by favourable working capital movements. In line with our outlook, normalised free cash flowb was £2,440m, down £533m or 18%, driven by increased cash capital expenditure, decrease in EBITDA and higher tax payments.
Free cash flow, which includes specific item outflows of £598m (2017/18: £828m) and a £273m (2017/18: £109m) tax benefit from pension deficit payments, was £619m (2017/18: £1,586m). Last year also included payments of £325m for the acquisition of mobile spectrum.
The spectrum auction bidding took place across the 2017/18 and 2018/19 financial years. Whilst £325m was on deposit with Ofcom at 31 March 2018, we went on to acquire spectrum for a total price of £304m and the excess deposit balance has since been refunded. We made pension deficit payments of £2,024m (2017/18: £872m) and paid dividends to our shareholders of £1,504m (2017/18: £1,523m).
The net cash cost of specific items of £598m (2017/18: £828m) includes restructuring payments of £372m (2017/18: £189m) and regulatory payments of £170m (2017/18: £267m). Last year also included payments of £225m relating to the settlement of warranty claims under the 2015 EE acquisition agreement.
b After net interest paid, before pension deficit payments (including the cash tax benefit of pension deficit payments) and specific items.
Question:
What is the average tax paid for 2017-2019?
Answer: -(431 + 473 + 551) / 3 = -485