1.   Relevant competent authorities shall make any calculations determining the principal trading venue for a share by at least 35 calendar days before the date of application of Regulation (EU) No 236/2012 in respect of the period between 1 January 2010 and 31 December 2011.

2.   Subsequent calculations shall be made before 22 February 2014 in respect of the period between 1 January 2012 and 31 December 2013, and every two years thereafter in respect of the subsequent two year period.

3.   Where the share concerned was not admitted to trading during the whole two-year period on the trading venue in the Union and the third country trading venue, the period for calculation shall be the period during which the share was admitted to trading on both venues concurrently.