Complex sentence: The last Lions victory in Wisconsin was a 21-17 win on December 15,1991, until the Lions' 18-16 victory in Green Bay on November 15,2015.
Split into simpler sentences: The last Lions victory before the streak began in Wisconsin was a 21-17 win on December 15,1991. The Lions ended the streak with a 18-16 victory in Green Bay on November 15,2015.