Complex sentence: According to the Bank for International Settlements, as of April 2016, average daily turnover in global foreign exchange markets is estimated at $5.09 trillion, a decline of approximately 5% from the $5.355 trillion daily volume as of April 2013.
Split into simpler sentences: According to the Bank for International Settlements, as of April 2016, average daily turnover in global foreign exchange markets is estimated at $5.09 trillion. This marks a decline of approximately 5% from the $5.355 trillion daily volume as of April 2013.