Local authorities are by law (Section 63(1) of the Local Government Act 2001) independent in the performance of their functions. The operation of the Tenant (Incremental) Purchase Scheme 2016 is a matter for individual local authorities, in line with relevant legislation, including the Housing (Sale of Local Authority Houses) Regulations 2015.
The data requested by the Deputy is not yet available. However, information on sale of local authority houses in previous years up to 2016 can be found on my Department's website at the following link:
http://www.housing.gov.ie/housing/statistics/social-and-affordble/other-local-authority-housing-scheme-statistics.