The RTE policy, (which the other stations appear to be following) is to only make ratings public when exceptionally high, or of selected relevance. For once, they've released the weekly top ten, as they were all on One - 571,000 for The Voice, it seems:
http://www.rte.ie/ten/news/2015/0105...rt-of-charlie/
http://www.rte.ie/ten/news/2015/0105...rt-of-charlie/



