The current page readability can be enhanced by adding and changing a bit the current layout and detailed presented.

2)  Below the header - add textual summery which includes aggregation of the information presented in the graph similar to the cppcheck plugin table or add it as another presentation available for the graph.

• The table above includes the number of warning for each severity.
  Yes, it is true that this information is presented in the graph and you can see the numbers once you hover the chart, but  it is also valuable to have it in table. (Maybe the chart can have two modes, textual and  graph)
• Moreover presenting the numerical delta from last build is very helpful 
• The same applies to the reference comparison graph