named and numbered after the site where they were located. For example, NA32 was an experiment looking at the production of so-called "charmed" particles and located at the Prévessin (North Area) site while WA22 used the Big European Bubble Chamber (BEBC) at the Meyrin (West Area) site to examine neutrino interactions. The UA1 and UA2 experiments were considered to be in the Underground Area, i.e. situated underground at sites on the SPS accelerator. Most of the roads on the CERN Meyrin and Prévessin sites are named after famous physicists, such as Wolfgang Pauli, who pushed for CERN's creation. Other notable names are Richard Feynman, Albert Einstein, and Bohr. Participation and funding Member states and budget Since its foundation by 12 members in 1954, CERN regularly accepted new members. All new members have remained in the organization continuously since their accession, except Spain and Yugoslavia. Spain first joined CERN in 1961, withdrew in 1969, and rejoined in 1983. Yugoslavia was a founding member of CERN but quit in 1961. Of the 23 members, Israel joined CERN as a full member on 6 January 2014, becoming the first (and currently only) non-European full member. The budget contributions of member states are computed based on their GDP. Enlargement Associate Members, Candidates: Turkey signed an association agreement on 12 May 2014 and became an associate member on 6 May 2015. Pakistan signed an association agreement on 19 December 2014 and became an associate member on 31 July 2015. Cyprus signed an association agreement on 5 October 2012 and became an associate Member in the pre-stage to membership on 1 April 2016. Ukraine signed an association agreement on 3 October 2013. The agreement was ratified on 5 October 2016. India signed an association agreement on 21 November 2016. The agreement was ratified on 16 January 2017. Slovenia was approved for admission as an Associate Member state in the pre-stage to membership on 16 December 2016. The agreement was ratified on 4 July 2017. Lithuania was approved for admission as an Associate Member state on 16 June 2017. The association agreement was signed on 27 June 2017 and ratified on 8 January 2018. Croatia was approved for admission as an Associate Member state on 28 February 2019. The agreement was ratified on 10 October 2019. Estonia was approved for admission as an Associate Member in the pre-stage to membership state on 19 June 2020. The agreement