10. Intangible assets

At December 31, 2014, intangible assets totaled €69,569 thousand and were subject to the following changes during the year:

(€ thousand)At December 31,
2013
Acquisition of Basildon plantAdditionsAmortizationDivestments
and other changes
Translation differencesAt December 31,
2014
Development costs              
- Gross carrying amount - 117,412 32,470 - - 6,283 156,165
- Accumulated amortization - (76,077) - (13,174) - (4,493) (93,744)
- Net carrying amount - 41,335 32,470 (13,174) - 1,790 62,421
Concessions, licenses and similar rights              
- Gross carrying amount 29 3,995 2,984 - 895 258 8,161
- Accumulated amortization (25) (3,446) - (262) - (205) (3,938)
- Net carrying amount 4 549 2,984 (262) 895 53 4,223
Intangible assets in progress and advances              
- Gross carrying amount 35 640 1,180 - (948) 45 952
Goodwill              
- Gross carrying amount 375 1,508 - - - 85 1,968
Other intangible assets              
- Gross carrying amount 69 - 5 - - - 74
- Accumulated amortization (53) - - (16) - - (69)
- Net carrying amount 16 - 5 (16) - - 5
Total Intangible assets 430 44,032 36,639 (13,452) (53) 1,973 69,569