[eru]

You'd have to correct the 47m GBP for nominal GPD/capita growth to get a clearer sense.

Using the data from http://www.theguardian.com/news/datablog/2009/nov/25/gdp-uk-... and picking 1975 nominal GPD (28,742 mGBP) vs 2013 nominal GDP (399,834 mGDP), the 47 mGBP in 1975 become 654 mGBP in 2013.