Country by Year of Independence - Europe

This quiz has many errors. A few examples: Estonia, Latvia and Lithuania became independent in 1991, after the Soviet Union collapsed (they were independent before, but so were many other countries in the quiz); Romania became independent in 1878, not in 1859; Norway became independent in 1905, not in 1814; Ireland became independent in 1919, not in 1937. You say in the description that we should use "the year that I consider to be their year of independence". What kind of rule is that? How can anyone know what you consider to be the correct date?