I was curious if anyplace in Shadowrun canon if it describes the different meta types occurring in less or greater numbers among different ethnicities on different continents. Did trolls, orks, dwarves and elves occur in any more frequency among Europeans, Africans, Asians, or Middle-Easterners?

There are notes in many of the older sourcebooks along these lines. I haven't closely looked at the SR4 setting books, but there might be something useful there.

The only demographics data I can recall off the top of my head:
* The Kingdom of Hawai'i has huge Ork and Troll populations. This is tied to genetic heritage, apparently.
* Cascade Ork has an abnormally large Ork population. I think this may have been more of a migration issue though.
* Also, the Tirs have a lot of elves. (I know, duh.) This may be another migration issue.

-paws

Tir na Nog had a big boost of elves being born, 40% of all children, I think. So did Britain during the Awakening, but that's more than likely because dwarves were being murdered in the cradle.

didn't europe get kinda more dwarves than most others?

Might have been parts of it that did. I know that the UK had a higher percentage of Dwarf births in the poorer north - explained by rumours of infanticide amoungst the nobility. The same goes for rks and trolls - rare to find their metatype expressed in the halls of power.

Bang on with Ireland having a huge elven birthrate of ~40%. Hawai'i and theother Polynesian islands were stated as having a higher ork heritage genepool. SR$ Runner's Companion also has a line about the Menehune dwarf variant there. Apparently the title also means "slave" in certain other Polynesian dialects. As for the Trolls - heavy expression among the Maori genepool in New Zealand/Aotearoa. Decided to make elves a little more rare down under whilst writing that bit.

Well, here are the percentages from Shadows of Europe:

I thought there was a large meta population in Germany near the black forrest

You're probably thinking of the Troll Kingdom Black Forest that has 48% trolls and 34% orks - then again, it has only 210,000 citizens total...

Yeah that was it, even with the low population, doesn't density of metas pop out or were the metas who migrated down?

The Troll Kingdom was born out of a metahuman resistance movement that formed in the 2030s as a response to the meta-racist policies in Germany's southern states (complete with mandatory registration and eventually concentration camps). It was founded as a safe haven for the goblinized and admitted to statehood when the AGS was formed in 2045.
My guess is most of the inhabitants moved there deliberately, they weren't born there.

ok, so in and around germany more dwarves,
south / east of germany and north of denmark more elves.
orcs and trolls generally less? O.o
that about it?

Thanks a lot for that, but unfortunately, i don't think these numbers would be used anymore in the current setting.
SR4 seems to have made a massive retcon of demographics.
AFAIK, in every sprawl detailed so far in SR4, we see an ork population somewhere around 20%.
RC describes them as the second most common metatype after baseline humans (which makes more sense than the SR3 numbers IMHO, given their abnormally high birth rates).
Elves rank second, with seemingly a little less than 10% worldwide (they are also said to express frequently in any population, even the most isolated ones), with dwarves being a little rarer.
Trolls are the most seldom encountered metatype, even not appearing at all in some ethnicities.

On average, the numbers seem to indicate that we are looking at around 64% humans (this number is confirmed in RC), 20% orks, 9% elves, 5% dwarves, 2 percent trolls and 1% other sapients.
I'd guess that these 1% are mostly ghouls and to a lesser extend other Infected, given how low the numbers for nonmetahuman sapients in RC are.
According to (ingame) statistics, there's probably less than a million nonmetahuman sapients around, most of them being shapeshifters and AI, so unless there's a large number of yet undescribed other sentient species, Infected would have to make up for almost all of the 1% others.

I always took most of the published numbers from SR1–SR3 to be official numbers from a census, circa 2050. Hence they would underestimate the SINless, and therefore some of the orks and trolls.

By SR4—two decades later—there would be even more orks and trolls due to their breeding rates, which fits the newer numbers being used.

Orks (maybe Trolls too ?) die youger though, so that would reflect in percentage of population, maybe even to the point of completely negating that fertility "bonus". I don't recall what is the norm for ork "litters", but they do die at 40 years old, so even if the average is two per "litter", there wouldn't be any growth in Ork proportion.

I say it a lot, but it bares repeating: Buy the "Shadows of..." books. They're a brilliant resource, even for SR4. Whilst I agree that the numbers will have shifted, it's not hard to just bump everything a little more towards the metas, especially Orks. Even with that, the "Shadows of" books are a great guideline, and a fantastic resource in general.

Well, if you total and average the numbers from SoE you get:
67.29% Human
10.35% Elf
09.18% Ork
07.24% Dwarf
04.71% Troll
01.29% Other

If you take the numbers from SoE as recent at the in-game publishing date they're from 2063.

And here's an example of demographics changing over time in the Allied German States:

That's 75% more orks in 10 years - and 41% less dwarves though I'm at loss why.

Trolls have a slightly shorter life expectancy than humans, but about the same birth rate.

Ork litters, on the other hand, typically include four children, sometimes going up to eight.