IFRS balance sheet items
Our total investment in joint ventures was £524.1 million at 31 December 2019 (which includes investments in joint ventures of £326.6 million and loans to joint ventures £197.5 million), a decrease of £299.8 million from 31 December 2018. The key driver in the year related to the share of loss of joint ventures of £158.9 million, which primarily included underlying earnings of £27.9 million and a property revaluation deficit of £182.9 million, a £200.7 million transfer of intu Puerto Venecia and intu Asturias to held for sale, partially offset by the residual interest in intu Derby of £93.9 million being classified as a joint venture.
We are exposed to foreign exchange movements on our overseas investments. At 31 December 2019 the exposure was 24 per cent of net assets attributable to shareholders, the increase from the 31 December 2018 exposure of 15 per cent being due to the property revaluation deficit in the UK. Adjusted for the disposals in intu Puerto Venecia and intu Asturias, this exposure would be reduced to 15 per cent.
1 A reconciliation from the IFRS consolidated balance sheet to the amounts presented above is provided in the presentation of information on page 159. A further reconciliation of EPRA NAV to IFRS net assets attributable to owners of intu properties plc is provided within EPRA measures on page 169.
2 Other assets and liabilities includes property, plant and equipment, other non-current assets, trade and other receivables, trade and other payables, current tax liabilities, deferred tax liabilities and other payables.
3 Relates primarily to our partner’s 40 per cent stake in intu Metrocentre. The amount is considered to be recoverable in view of the £195.4 million owed to the non-controlling interest (which is included in the Group’s borrowings in note 23).
4 Other adjustments relate to fair value of derivative financial instruments, fair value of convertible bonds, deferred tax on investment and development property, share of joint ventures’ adjusted items and non-controlling interest recoverable balance not recognised in EPRA NAV.
The key drivers in the decrease in IFRS net assets attributable to owners of intu properties plc of £1,907.5 million as well as the decrease in EPRA NAV of £1,969.8 million and EPRA NAV per share of 146 pence in the year are discussed below.
A Investment and development property
Investment and development property has decreased by £2,534.1 million:
—deficit on revaluation of £1,979.7 million (see E above within the income statement section)
—disposals in the year, including the part disposal of intu Derby in July 2019, transfer of intu Puerto Venecia and intu Asturias to assets held for sale (see B below) and sundry asset disposals
—capital expenditure of £129.2 million on projects enhancing the value and appeal of our centres, including £44.5 million on the Primark anchored intu Trafford Centre’s Barton Square extension, £14.5 million on the redevelopment of intu Broadmarsh and £11.2 million on the now completed leisure extension at intu Lakeside
B Joint ventures and other assets classified as held for sale
intu Puerto Venecia and intu Asturias were classified as joint ventures held for sale at 31 December 2019 and recognised at their expected net proceeds.
intu Puerto Venecia
In December 2019 the Group announced the disposal of its joint venture interest in intu Puerto Venecia to Generali Shopping Centre Fund S.C.S. SICAV-SIF and Union Investment Real Estate GMBH for €475.3 million (intu share €237.7 million), an 11 per cent discount to the June 2019 valuation. This is expected to complete in early April and deliver net proceeds to intu of around £95.4 million after repaying asset-level debt, working capital adjustments, fees and taxation.
Table:
£m | Notes | 2019 | 2018 | Change
Investment and development property | A | 6,721.6 | 9,255.7 | (2,534.1)
Joint ventures and other assets classified as held for sale | B | 163.7 | – | 163.7
Investment in associates | C | 53.7 | 65.6 | (11.9)
Net external debt | D | (4,498.4) | (4,867.2) | 368.8
Derivative financial instruments | E | (286.9) | (284.0) | (2.9)
Other assets and liabilities2 |  | (307.7) | (342.0) | 34.3
Net assets |  | 1,846.0 | 3,828.1 | (1,982.1)
Non-controlling interest3 |  | 58.2 | (16.4) | 74.6
IFRS net assets attributable to owners of intu properties plc |  | 1,904.2 | 3,811.7 | (1,907.5)
Other adjustments4 |  | 73.1 | 135.4 | (62.3)
EPRA NAV |  | 1,977.3 | 3,947.1 | (1,969.8)
EPRA NAV per share (pence) | F | 147p | 293p | (146)p


Question: What is the percentage change in the EPRA NAV from 2018 to 2019?
Answer: -49.9
Calculation: -(1,969.8/3,947.1)