The data is derived from the Scottish Assessors’ Valuation Roll, and local authorities’ billing data, as at: end March 2011, end April 2012, 1 October 2013, 8 October 2015, 5 October 2016, 1 June 2018, 31 May 2019, 1 July 2020, 1 June 2021, and 1 July 2022.