Source: http://listedtech.com/lms-providers-market-share-implementation-year/
Keep in mind that Blackboard (BB) growth has been through acquisitions. This has proven to be an effective strategy for BB because changing from one LMS to another is one of the most challenging IT task an institution can take on. The chart above points to % of LMS implementation and shows just how quickly Canvas has grown and continues to grow.
The chart below reveals the total market share and provides a better perspective the dominant players in this space. While BB is still the market leader their growth has almost stopped and ask Moodle and Canvas continue to grow it will more than likely be at the expense of BB market share.
Source: http://listedtech.com/lms-providers-market-share-implementation-year/
If I were D2L I would be very concerned about Canvas and Moodle because D2L no longer is a compelling alternative to BB. Having worked with all these LMS at a variety of institutions I am not surprised to see Canvas grow. It really does provide a genuine alternative to the traditional LMSs BB, Moodle and D2L.