Consolidation

A private company acquires a 45% share in a joint venture which is LLP as on Sep2009...Again as on April,2013 there is a reconstitution in the agreement and share of private co. comes to 40%. I have to consolidate joint venture LLP with d private company as on 31.3.2016 ...For this I shall be calculating cost of capital as on September.2009 taking 45% as share...Do I need to calculate cost of capital again as on April,2013 with 40% share ???If yes, what treatment should be done for d difference that arises on account of goodwill/capital reserve??? And if other process to be done, what should be done???