16. Restricted cash

Restricted cash amounted to €7.7 million on 31 December 2016, and decreased to €1.2 million on 31 December 2017. This decrease is mainly related to the full release of the €6.6 million escrow account containing part of the proceeds from the sale of the service division in 2014, after final agreement with Charles River was reached in the first quarter of 2017. This decrease was slightly offset by an increase in non-current restricted cash of €0.1 million due to additional bank guarantees with regard to the rental of supplementary office space for the Belgian premises.

Restricted cash on 31 December 2017 was composed of bank guarantees on real estate lease obligations in Belgium and in the Netherlands for €0.45 million and €0.7 million respectively.