SonarQube used to have dashboards which were quite convenient to display how metrics changed over time. There was even a dashboard called "Time Machine".
How can I see this sort of information in SonarQube 6.1? I appreciate the new focus on the "leak period" but this is not everything I care about.
Go to the project's Measures space and drill in on the metric of interest. You should find a history graph there.
UPDATE These history graphs moved into the Activity page in 6.3