From the data tool (data.cpdp.co), you can filter by year or month. Just type in a year into the search bar (for example, "2016", "2015", "2014", etc.) and select from the "Incident Year" results. If you want to search for a specific month, then you can type in a month and year (for example,“May 2012”).
You can download all the complaints information for that year by clicking the "Download Table" button.