I know the speed of light is measured in km/h but in my experience it is more commonly used to measure distance.

I understand that at the begining the universe was 50-50 matter/anti-matter but, if we look at simple physics eg. Newtons laws, then I believe we can see the relationship they hold to one another. Namely energy cannot be destroyed or created, only changed. We thus need to assume that it requires less energy to generate matter then anti matter hense the larger quantinty of matter.

Now, if assume that the universe is 15billion years old, then we already have a time factor to use.

And I agree, using light as a measure is not at all viable in the universe as in is not a constant.