There is a Biannual litter count (Every Year May & November) that is done over 74 sites surveyed/counted through out Northern Territory.
Each site survey area 1,000 Sq M and the site types include a variety of sites.
A key outcome of the report is that
When all plastic bags are compiled together you see a trend that shows an approx. 40% increase in plastic bag litter over the last 7 years
Here are some of the results from the survey: