At 31 December 2018 and 2017, the Group had made undertakings concerning future minimal rental payments by virtue of non-cancellable operating lease agreements, which expire as set out in the table below.

The current value of the rental payments has been calculated by applying a post-tax discount rate in keeping with the cost of capital of each of the countries and includes the commitments which the Group estimates will have to be met in the future to guarantee a fixed income or minimum return from hotels operated under a management agreement.

The term of the operating lease agreements signed by the Group ranges from 5 to 40 years. Agreements likewise include several methods to determine the rent to be paid. Basically, the methods for determining rentals can be summarised as fixed rentals indexed to a consumer price index; fixed rentals complemented by a variable part, indexed to the property’s operating profits; or completely variable rentals, determined by business performance during the year. In some cases, variable rentals are set with a minimum profitability threshold for the owners of the property under operation and sometimes this minimum threshold has a limit on payments made which restricts the amount of minimum rents that would be paid.

The breakdown by business unit of the current value of the rental instalments at 31 December 2018 is as follows (thousand euros):

The breakdown by business unit of the current value of the rental instalments at 31 December 2017 is as follows (thousand euros):