 Complete the following phrase:  Since the 1970s, Bayerns main rivals have been the clubs who put up the strongest fight against its national domice. In the 1970s this was Borussia Mönchengladbach, in the 1980s the category expanded to include Hamburger SV. In the 1990s, Borussia Dortmund, Werder Bremen and Bayer Leverkusen emerged as the most ardent opponents. Recently Borussia Dortmund, Schalke, and Werder Bremen have been the main challengers in the Bundesliga. Recently, Bayerns main Bundesliga challenger has been Borussia Dortmund. Bayern and Dortmund have competed against each other for many Bundesliga titles. They also have played against each other in the DFB-Pokal final in 2008, 2012, 2014, and 2016. The 25 loss against Dortmund in the 2012 final was Bayerns worst ever loss in a DFB-Pokal final. Bayern and Dortmund have also played against each other in the DFL-Supercup in 1989, 2012, 2013, 2014, 