I am advised by the Revenue Commissioners that the Commissioners publish income distribution statistics based on incomes filed in tax returns. Income Distribution Statistics are published on Revenue's statistics webpage at http://www.revenue.ie/en/about/statistics/index.html.
For example, in 2012 (the most recent year for which tax returns are filed and processed), 37,200 taxpayer units have income of €150,000 or over. These cases report income of €10.5 billion in total and paid combined Income Tax/Universal Social Charge (USC) of €3.9 billion. From the total population for 2012, these cases represent 1.8% of income earners, account for 13.2% of total income and 25.5% of Income Tax/USC paid.
Married persons or civil partners who have elected or who have been deemed to have elected for joint assessment are counted as one tax unit.