What percentage of the parallel lives for an average person are experienced by the soul extension in their current life they experience as their self?

As we told you, this would be 100%. It is all you, all the time, essentially multitasking in a series of lifetimes generated, but experienced in parallel, on the same looping of time. So all are important, all are personal to you in particular, and this again is why they all have great importance. They will have an impact and they are all assignable to you in terms of responsibility, so the more you do to make the best of those life experiences and the opportunities you have to become more enlightened with healing to address any irregularities, will be of direct benefit to you especially, as an aspect of your soul.