At what percentage of negative course feedback do you update a course?

We create and publish eLearning for external customers, and these customers can voluntarily provide comments via a free-text field. At what point would you act on a common complaint and update the course. For example, lets say the only common complaint was "Wish there was more interaction".  Would you update the course, which consumes precious time and resources, to add more engagements or simulations when only 5% of the feedback states a similar sentiment? or 10%? etc. I'm wondering if there is an industry standard.  We realize you can never make everyone happy, so I don't want to make course updates to appease just a few.  I'm interested in hearing how others determine when to pull that trigger.