The average tax and social security burden on employment incomes increased in 26 out of 34 OECD countries in 2011 according to the new OECD Taxing Wages publication. Tax payers in Ireland, Luxembourg, Portugal and the Slovak Republic were among those hit with the largest increases. Those in New Zealand and the United States saw their tax burden fall. In Hungary, the average single worker without children was faced with the largest increase in the tax wedge, but for families with children, it fell.here is a chart:
You can look at the data here.