51% group companies

Hi Sir,
A company is a related 51% group company if the parent company owns directly or indirectly more than 50%
of the share capital of the subsidiary company at the end of the previous accounting period.

Is for a 75% group relief group the parent should own at least 75% of the share capital of the subsidiaries AT THE END OF THE PREVIOUS ACCOUNTING PERIOD?

Is this also applies for a 75% gains group ?