Why are there so many famous Irish male actors but not female?

I mean this in the Hollywood movie sense. Of course there are female actors regarded as famous in within Ireland but I can't think of any in Hollywood. On the other hand, there are a number of male actors I can think of off the top of my head- Liam Neeson, Colin Farrell, Cillian Murphy, Pierce Brosnan, Brendan Gleeson, Jonathan Rhys Meyers, Peter O Toole, to name but a few.