I am actually looking for this feature which was earlier there in OJS 2.
How to show Article statistics (Articles submitted, Accepted, Rejected in a year or previous year) [OJS 3.1]
I dont know is there any plugin for this job or not, but with a simple guess i thing you can use SubmissionDOA object to extract this information. in this class there is a method named “getByStatus” witch you can give the state and journal id to retrieve the submissions, so you can use them to calculate this statistics. the available states are defined in top of the Submission Class.