1819. The value of the Assignation rubles fell relative to the coins until, in 1839, the relationship was fixed at 1 silver ruble = assignat rubles. In 1840, the State Commercial Bank issued 3, 5, 10, 25, 50 and 100 ruble notes, followed by 50 ruble credit notes of the Custody Treasury and State Loan Bank. In 1843, the Assignation Bank ceased operations, and state credit notes (Russian: , ) were introduced in denominations of 1, 3, 5, 10, 25, 50 and 100 rubles. In 1859 a paper credit ruble was worth about nine-tenths of a silver ruble These circulated, in various types, until the revolution, with 500 ruble notes added in 1898 and 250 and 1000 ruble notes added in 1917. In 1915, two kinds of small change notes were issued. One, issued by the Treasury, consisted of regular style (if small) notes for 1, 2, 3, 5 and 50 kopeks. The other consisted of the designs of stamps printed onto card with text and the imperial eagle printed on the reverse. These were in denominations of 1, 2, 3, 10, 15 and 20 kopeks. Provisional Government issues In 1917, the Provisional Government issued treasury notes for 20 and 40 rubles. These notes are known as "Kerenki" or "Kerensky rubles". The provisional government also had 25 and 1,000 ruble state credit notes printed in the United States but most were not issued. Soviet ruble The Soviet ruble replaced the ruble of the Russian Empire. The Soviet ruble (code: SUR) was the currency of the Soviet Union between 1917 and the breakup of the Soviet Union in 1991. The Soviet ruble was issued by the State Bank of the USSR. The Soviet ruble continued to be used in the 15 Post-Soviet states. The Soviet ruble was used until 1992 in Russia (replaced by Russian ruble), Ukraine (replaced by Ukrainian karbovanets), Estonia (replaced by Estonian kroon), Latvia (replaced by Latvian ruble), Lithuania (replaced by Lithuanian talonas), and until 1993 in Belarus (replaced by Belarusian ruble), Georgia (replaced by Georgian lari), Armenia (replaced by Armenian dram), Kazakhstan (replaced by Kazakhstani tenge), Kyrgyzstan (replaced by Kyrgyzstani som), Moldova (replaced by Moldovan cupon), Turkmenistan (replaced by Turkmenistani manat), Uzbekistan (replaced by Uzbekistani sum), and until 1994 in Azerbaijan (replaced by Azerbaijani manat) and until 1995 in Tajikistan (replaced by Tajikistani ruble). Symbol The ruble sign “₽” is a currency sign used to represent the