This is probably the best measure of how average living standards have progressed through time: it takes into account the lift in productivity, changes in the relative prices of our exports and imports, and changes in the share of the population that is in paid employment. It is the strongest of the three lines shown here.
This reflects the fact that over the past two decades or so there has been a substantial increase in the share of the population in paid employment; between 1993 and 2008, this share rose by 7 percentage points to over 50 per cent.