sentences:  At the same time in 2006 around 9% of Estonia's residents were of undefined citizenship.While there have been calls for the return of all Estonia's Russians to Russia, the Government of Estonia has been adopting an integration policy, advocating an idea that Estonia's residents should possess at least a basic knowledge of the Estonian language.People who arrived in the country after 1940 qualify for naturalization if they have general knowledge of Estonian language and the Constitution, have legally resided in Estonia for at least eight years, the last five of them permanently, have a registered place of residence in Estonia and a permanent legal income.