Forcing a ROUND() Cell to be a Constant Number

This might end up being more of a math question than an Excel question -- but the way my spreadsheet's set up so far is that each employee should have a goal of, say, 100 for how many people they need to sign up. But they each have specific geographic breakdowns in their turf, some of which might be bigger or smaller than others, but at the end should all add up to 100 for each employee.

It's not super hard to do since I just take a goal of 100, in this example, and multiply it by the percent of population of the area in their overall assignment and give them a goal for that area based on that. So if Philadelphia has 70% of their total population, Upper Darby has 20% of their total population, and Phoenixville has 10% of their total population -- the goals would come out like this:

Philadelphia, Goal: 70
Upper Darby, Goal: 20
Phoenixville, Goal: 10
Ryan, Total Goal: 100

For some of the employees, that works out perfectly -- but based on the population sizes, the rounding sometimes gets a little off and it could end up like this:

Philadelphia, Goal: 71
Upper Darby, Goal: 19
Phoenixville, Goal: 11
Ryan, Total Goal: 101

For most employees, it ends up being dead-on 100 -- but there are some whose totals are at 98 or 99 or 101, and I was wondering if there was a way to force it to shave a point off or add a point on somewhere, pending on how close the decimal was when it rounded to make sure that it always ends up exactly on 100. (I'm using 'Data >> Subtotals' to get what's being represented above as "Ryan, Total Goal.")

Thanks for the help!

[Edit: Here's a spreadsheet to better see what I'm talking about. Doesn't exactly match the example above, but it's close:
SubtotalForcedConstantExample.xlsx]