We have a PI tag that currently gets fed with the prior month's engine run hours. We also have a tag that is updating in real-time with the run hours for the current month. What is the best way to set up a method whereby I could have a running total for the year? I am wanting to be able to track this so that we could have a notification if run hours for engines that have restricted run hours related to emission etc are starting to reach some threshold. This running count would start over each year obviously.