For those eligible to claim vehicle expenses, there is a simplified method of calculating business mileage. What does one enter on the T777 for mileage then?

For those eligible to claim vehicle expenses, there is a simplified method of calculating business mileage. As per: https://www.canada.ca/en/revenue-agency ... cords.html

I now have figured out what needs to be done. That said, what baffles me is how one would go about using the simplified method. E.g. On the T777, one is required to put down "total business mileage" and "total annual mileage" for the form. Well, if I use the simplified method, what do I enter then? I cannot enter just the quarter that I am required to calculate because as per the maths, it just doesn't work out that way.

Eg: 2018 total mileage = 75% business
2018 Q1: 86%
2019 Q2: 89%

It would then be:

.89/.86*.75 = .776

Or 77.6% using the simplified method in 2019. Would I just "extrapolate" for the T777 and ensure whatever numbers I enter end up at 77.6%?