In 1991, Crimea voted to leave Ukraine and become an autonomous republic of the USSR. Of course, the USSR disbanded later in 1991, and Crimea became an autonomous region in Ukraine.
In 1994, Crimea's independence and pro-Russia movement was growing, and Crimea formed a separatist government.
the UN polled Crimea quarterly from 2009 - 2011, and each time found that a majority of Crimean residents wanted to rejoin Russia.
In 2014, around the time of the Maiden coup in Kiev, and pre-referendum in Crimea, various international pollsters found that nearly 80% of polled Crimean residents wanted to rejoin Russia.
Post Crimean referendum, many international pollsters investigated the satisfaction of Crimeans with the referendum outcome, and typically found that over 85% of Crimeans were fully satisfied with the referendum outcome, while further Crimeans were mostly or generally satisfied with the 2014 Crimean referendum outcome.
The polling of Crimea is consistent and clear.