02/03/2020: COVID-19 impact
                 The outbreak of the COVID-19 pandemic resulted in economic disruptions, affecting the Ukrainian Hryvnia and causing volatility in the currency markets.
                 06/05/2015: Pegged to the euro
                 The Bulgarian Lev officially became a currency pegged to the euro, maintaining a fixed exchange rate, on May 6, 2015.
                 05/02/2015: Currency devaluation
                 Due to the economic crisis, the Ukrainian Hryvnia experienced a significant devaluation, leading to a sharp increase in prices and financial hardships.
                 20/02/2014: Ukrainian revolution
                 The Ukrainian revolution began, leading to political instability and economic challenges, impacting the value and stability of the Ukrainian Hryvnia.
                 01/07/2008: Exchange rate flexibility
                 Ukraine implemented a flexible exchange rate system, allowing the Ukrainian Hryvnia to fluctuate based on market forces rather than being pegged to a fixed rate.
                 01/10/2004: Banknote redesign
                 New banknotes of the Ukrainian Hryvnia were issued with enhanced security features and updated designs, aimed at combating counterfeiting.
                 01/01/2002: Replacement of notes and coins
                 New series of notes and coins for the Bulgarian Lev were introduced, replacing the previous designs on January 1, 2002.
                 01/07/1999: Currency board arrangement
                 Bulgaria implemented a currency board arrangement, fixing the Bulgarian Lev to the euro at a rate of 1.95583 on July 1, 1999.
                 02/09/1996: Currency reform
                 A currency reform was conducted, introducing new banknotes and coins of the Ukrainian Hryvnia, addressing issues of inflation and stabilization.
                 02/09/1992: Introduction of the Ukrainian Hryvnia
                 The Ukrainian Hryvnia (UAH) was introduced as the national currency, replacing the Soviet ruble, marking Ukraine's economic independence.
                 15/09/1962: Introduction of the New Lev
                 The New Lev was introduced as a new currency in Bulgaria, replacing the Lev A, on September 15, 1962.
                 01/12/1952: Lev replaced by Lev A
                 The Bulgarian Lev was replaced by a new currency named Lev A on December 1, 1952 as a result of currency reform.
                 14/10/1923: Hyperinflation
                 Bulgaria experienced severe hyperinflation, causing the value of the Lev currency to plummet during the period from 1923 to 1924.
                 01/04/1881: Introduction of the Lev
                 The Bulgarian Lev currency was introduced as the official currency of Bulgaria on April 1, 1881.