1 Countries shown in italics are using alternative measures of income and interest rates, for more details please see the Data documentation. Annual figures refer to the average of the year. DSRs are derived from aggregated data based on a unified methodology which captures the dynamics of DSRs over time. It is more meaningful to compare national DSRs over time (by, for instance, removing country-specific means) rather than compare their absolute levels which are difficult to pinpoint. This approach also takes account of different institutional and behavioural factors affecting average remaining maturities.