Reader’s guide

Conventions

In each figure, data labelled “OECD” are simple mean averages of the OECD countries displayed, unless otherwise indicated. Where data are not available for all 35 OECD countries, the number of countries included in the calculation is specified in the figure (e.g. OECD 33). Where changes over time are shown in the figures, the OECD averages refer to only those countries with data available for all time points.
When population-weighted OECD averages are used, this is specified in the figure notes. This refers to the mean average, weighted according to the size of the population in different countries, as a proportion of the total OECD population. This procedure gives more weight to countries with a larger population, relative to those with a smaller population, and enables inferences to be made about the “average OECD person” (rather than focusing on the “average OECD country”).
Each figure specifies the time period covered, and figure notes provide further details when data refer to different years for different countries.
Data for key partner countries, where available, are presented in a separate part of the figure to OECD countries.