Revenue Statistics - provisional data on tax ratios for 2015
New OECD Revenue Statistics data for 2015
New OECD data in the annual Revenue Statistics publication show that tax revenues as a percentage of GDP continue to recover gradually from the falls in almost all countries in 2008 and 2009 that stemmed from the financial and economic crisis. The average tax to GDP ratio in OECD countries was 34.3%1 in 2015 compared with 34.2% in 2014 and 33.8% in 2013.The 2015  figure is the highest recorded OECD average tax to GDP ratio since records began in 1965. (Table 1.1, Table 1.2)
Denmark had the highest tax to GDP ratio in 2015 (46.6%) and Mexico the lowest (17.4%).
Of the 32 countries for which data for 2015 are available, the ratio of tax revenues to GDP compared to 2014 rose in 25 and fell in 7.
Between 2014 and 2015, the largest tax ratio increases were in Mexico (2.3 percentage points explained by an increase in taxes on income and profits and in taxes on goods and services as a percentage of GDP) and in Turkey (1.3 due to higher revenues from taxes on goods and services and higher social security contribution revenues). Other countries with increases in their tax to GDP ratio between 2014 and 2015 of more than one percentage point were Estonia, Greece, Hungary and the Slovak Republic.
The largest falls in the tax ratio between 2014 and 2015 were in Ireland (5.1 percentage points, due to exceptionally high GDP growth in 2015), Denmark (3 percentage points, due to a fall in revenues from taxes on income and profits) and Iceland (1.8 percentage point). Luxembourg also showed a fall of more than one percentage point.
Compared with 2007 (pre-recession) tax to GDP ratios, the ratio in 2015 was still down by more than 3 percentage points in two countries (Ireland and Norway). The biggest fall has been in Ireland, from 30.4% in 2007 to 23.6% of GDP in 2015. Excluding Ireland, the largest fall has been in Norway, from 42.1% of GDP in 2007 to 38.1% in 2015.
The tax burden in Turkey increased from 24.1% to 30.0% between 2007 and 2015. Two other countries (Greece and Mexico) showed increases of 4 percentage points or more over the same period.
 Calculated by applying the unweighted average percentage change for 2015 in the 32 countries providing data for that year to the overall average tax to GDP ratio in 2014.