The bar chart provided depicts the quantity of waste collected by a recycling centre over the course from 2011 to 2015.
Overall, the period witnessed an upward trend in waste collection of four types of waste. Among those types, paper was always collected with the highest amount.
In 2011, the number of paper being collected ranked first with 57 tons, followed by glass with 48 tons. Both figures declined in the next year, but after that while paper collection kept falling to 40 tons, that of glass rose to its original level in 2011. The next 2-year period experienced increases in paper and glass collection to roughly 70 and 52 tons, respectively.
Initially, the data of tins and garden stood at 35 and 32 tons, respectively. By 2013, both had fallen, even garden collection almost halved, before growing to as high as they were in 2011. Afterwards, tins collection increased slightly to 39 tons, 4 tons higher than garden collection.