Usage dashboard - bar chart click function broken

[gjacob24]

Please complete the following fields as applicable:

What version of the DMPRoadmap code are you running? (e.g. v2.2.0) v4.1.1

Expected behaviour: If a user clicks on one of the bars in the chart graph representing 'No. of users joined during last year' or 'No. plans during last year', it should take them to the list of users/plans created in that month

Actual behaviour: The following error is thrown when you click on a bar in the abovementioned charts: Uncaught TypeError: chart.getElementAtEvent is not a function

Steps to reproduce: Note: this requires admin permissions Admin menu > Usage Click on 'Statistics on your Users' Click on a bar in the chart titled 'No. of users joined during last year' or 'No. of plans during last year'