The first column represents the amounts of unpaid fines per library from June 27, 2007 to November 20, 2014. Then, there are 3 columns for the amounts paid for the years 2012, 2013 and 2014. The amounts for the year 2014 are as of November 19, 2014.
The fines are for late fees: http://bibliomontreal.com/abonnez-vous/retards/
Update of February 3, 2015
Addition of a second file containing data on the amounts of unpaid fines per library, but with a division by monetary brackets of: 0 to $2.99, $3.00 to $9.99, $10.00 to $19.99, $10.00 to $19.99, $20.00 to $19.99, $20.00 to $49.99, $50 and more.