Sorting reports within a workspace other than numbering

I know that there is no functionality to sort reports within a workspace other than alphabeticaly,however, I am looking for a solution that would solve the following issue. 

I am using numbers to keep the most recent reports on top of the workspace, but this is a tidious job every month when a new report is released (I basically have to reassigned numbers for each report in the workspace to keep the most recents one on top). Moreover, I encountered a problem where simply using numbers works up to number 9 only. Please see the screenshot below (my workspace I wish to sort by the most recent added):