XP points and Km ridden for levels up

I have a question because I do not understand how does it work the levels up calculation.

I tray to explain my doubt.

I have found a very usefull table on titaniumgeek.com that shows on each level what you are going to unlock, how many XP point you will need and how many KM (or miles) you will need to ride to each level.

The thing that I do not understand is for example that after 500 km ridden I reach the 9th level and I should have earned 10000 XP points, but there are little bonus of 10 XP that I earn when I am riding.

So how it is possible to have the same XP points of the table when you earn more than Km ridden?

I hope to have been clear with my explanation…

you get the extra xp when you complete the hill climb, the sprint race, and complete a lap. also when you cross those lines you can a random item and if its a plus sign that is extra xp. those are the ones I know at least.

What about the ski lift to portal down epic KOM?