The Directorate General of the Civil Service has published the annual statistics on the perceptions of the elected positions of the Local Corporations (8,129 Municipalities and 52 Deputies, Councils and Island Councils) and the salaries assigned to the posts of officials of Municipalities, Autonomous and Provincial Councils and Councils and Councils during the 2020 Year.
The Administration Post Information System (ISPA), managed by the Secretariat of State for Civil Service, is the platform for collecting information on such data.
For more information on the website of the Ministry of Finance and Public Service, and within Civil Service, in the section on ISPA Space Statistics
https://www.mptfp.gob.es/portal/funcionpublica/funcion-publica/ispa/estadist_ISPA.html