The problem description is not clear to me.
What do you mean by "another set of data that follows a similar distribution"? Similar to what?
Seconldy, what is the meaning of "possible" and "actual"?
You question is unclear. If you want to estimate a new total percent by including the additinal data you are getting you must have quantity associated with your percentage so that you can create a meaninful weighted average.
If you want to determine if the new set of data has a different distribution than the historical data there are several tests mostly doing obtuse calculations on cummulative actual vs. expected percentages of values falling underneath a particular value. There is a lot of literature on the subject on comparing the distributions of two populations.
For paired samples Wilcoxon-Rank is a standard method if you can make no assumptions about the distribuion of the data. For non paired data non-parametric statistics exist but they require some in depth study.
Step-1: If your overall percentage 17% → 30% then, Actual (total) 105 → ~189.
Step-2: This number needs to be distributed over all elements in Actual column
From here things become non-linear, and we need some formula for arriving at Actual from POssible. And this needs to be a function of total.
i.e., function (possible, total (actual)) = actual.
If we can arrive at the above, then it might work ;)