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Share-Based Compensation (Tables) | 6 Months Ended
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Jun. 30, 2018
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Summary of Performance-Based RSU | The following table lists the inputs to the model used for the PSUs granted in May 2018:
Fair value at grant date (in Euros) |  |  | 15.31 |
Share price at grant date (in Euros) |  |  | 10.27 |
Dividend yield |  |  | — |
Expected volatility |  |  | 75 | %
Risk-free interest rate (U.S. government bond yield) |  |  | 2.60 | %
Model used |  |  | Monte Carlo |
Summary of Movements in Shares | The following table illustrates the number and movements in shares during the period:
|  | Performance- Based RSU |  |  | Restricted Stock Units |  |  | Equity Award Plans |  |  | Total |
|  | Potential Shares |  |  | Potential Shares |  |  | Potential Shares |  |  | Potential Shares |
At January 1, 2018 |  |  | 3,257,840 |  |  |  | 944,500 |  |  |  | 95,340 |  |  |  | 4,297,680 |
Granted(A) |  |  | 701,109 |  |  |  | 587,786 |  |  |  | 30,709 |  |  |  | 1,319,604 |
Over-performance(B) |  |  | 295,517 |  |  |  | — |  |  |  | — |  |  |  | 295,517 |
Vested |  |  | (34,580 | ) |  |  | (80,000 | ) |  |  | (68,136 | ) |  |  | (182,716 | )
Forfeited(C) |  |  | (134,163 | ) |  |  | (27,059 | ) |  |  | — |  |  |  | (161,222 | )
At June 30, 2018 |  |  | 4,085,723 |  |  |  | 1,425,227 |  |  |  | 57,913 |  |  |  | 5,568,863 |
(A) | For PSUs, the number of potential shares granted is presented using a vesting multiplier of 1.
(B) | When the achievement of TSR performance exceeds the vesting multiplier of 1, the additional potential shares are presented as over-performance shares.
(C) | For potential shares related to PSUs, 106,163 were forfeited following the departure of certain beneficiaries and 28,000 were forfeited in relation to the non-fulfilment of performance conditions.

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- Definition Disclosure of number of other equity instruments. + References No definition available. + Details
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- Definition The disclosure of information about indirect, by reference to the fair value of the equity instruments granted, measurement of the fair value of goods or services received as consideration for the entity's other equity instruments (ie other than share options). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 2 -IssueDate 2017-01-01 -Paragraph 47 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2017-03-01&anchor=para_47_b&doctype=Standard -URIDate 2017-03-09 + Details
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