The provided bar graph illustrates the quantity of waste collected by a recycling center over a period of five years, from 2011 to 2015, measured in tons.
Overall, the waste collected was classified into four categories: paper, glass, tins, and garden. It is notable that paper waste dominated the collection in most years, except for 2013, when glass waste was the highest. Garden waste consistently had the lowest collection levels, dropping notably in 2012.
In 2011, the recycling center collected 57 tons of paper waste, which decreased by 7 tons in 2012, but substantially increased to 70 tons in 2015. Similarly, garden waste decreased from 32 tons in 2011 to only 15 tons in 2012. The tin waste collection remained relatively consistent over the five-year period, except in 2012, when it dropped to 27 tons.
The collection of glass waste remained consistent at 48 tons in both 2011 and 2013. However, it fluctuated in the subsequent years, reaching 39 tons in 2015. Overall, the data indicates fluctuations in waste collection levels, with paper waste showing the most significant variations over the five-year period.