Negotiations began and in 1972 the Treaty of Accession was signed. Member countries must sign and ratify all WTO agreements on accession. The remaining states are committed to join the euro through their Treaties of Accession. China concluded multilateral negotiations on its accession to the WTO in September 2001. Historians agree that this condition improved upon his accession to the throne. On 30 August 2014, Tymoshenko announced the start of preparations for the NATO accession referendum. The Saar held no separate referendum on its accession. Formerly, a new sovereign proclaimed his or her own accession. A nonbinding referendum in 2008 resulted in 73 percent of voters supporting NATO accession. In 2008, it indicated its interest to resume and conclude its WTO accession. Upon his accession he also devalued the Roman currency. Elizabeth subsequently played an important role in securing the accession of Henry VII in 1485. Kazakhstan also had a long accession negotiation process. In 1977, Elizabeth marked the Silver Jubilee of her accession. He established that Bulgaria almost has joined Greece in vetoing the accession talks.