Connells Survey & Valuation reports that almost half of residential property purchases were by First Time Buyers in July 2017. These results mirrored that from the UK Finance (Council of Mortgage Lenders) that following government tax interventions, First Time Buyer activity grew for the first half of 2017.
Connells Survey & Valuation also reported that Remortgaging activity increased from 26% of all mortgage activity in July 2011 compared to 36% in July 2017.

Source: http://www.mortgagesolutions.co.uk/news/2017/08/23/half-july-purchases-first-time-buyers/?utm_source=Adestra&utm_medium=email&utm_term=&utm_content=&
Source: https://www.cml.org.uk/news/press-releases/june-press-release/