Year Sterling (millions) 2011-12-31 21939 2012-12-31 18000 2013-12-31 16018 2014-12-31 15223 2015-12-31 14903 2016-12-31 14585 2017-12-31 15452 2018-12-31 14987 2019-12-31 15508 2020-12-31 21267 2021-12-31 19860 2022-12-31 18693 2023-12-31 16145