Cuz I like statistic and stuff I'll actually add to this in terms of numbers:
Piltover's champion pool is comprised of 8 champions (including Yordles, but their relationship with the Pilties post IoW removal is questionable)-
For a grand total of two male humans, two female humans, three male yordles and one un-sexed entity who is identified as female. The ratio here is 5:3 in favour of males.
Zaun's champion pool is comprised of 9 champions-
For a grand total of five male humans, one female human, one male rat and two un-sexed entities who both identify as male. The ratio here is 8:1 in favour of males.
Demacia's champion pool is comprised of 14 (12 not counting some anomalous dudes) champions-
For a grand total of four human males, six human females (including Shyvana), one otherworldly male, one otherworldly female, one yordle female and one un-sexed entity who identifies as male. The ratio here is 8:6 in favour of females, making Demacia the only nation in all of known Runeterra to more lasses than lads. Even discounting Kayle and Taric since their status in the new canon is dubious at best, the ratio's still 7:5 and still in favour of the lasses.
Noxus's champion pool is comprised of 12 champions (10 not counting Riven and Morgana)
For a grand total of five human males, four human females, two undead males and one otherworldly female. The ratio is 7:5 in male favour, but discounting Morgana and Riven (since Morgana's status right now is like Kayle's and Taric's and Riven's gone AWOL) that drops to 7:3/
Ionia's champion pool is comprised of 15 champions (14 if we discount Jax)-
Here there are six human males, four human females, one male yordle, two humanoid males and two humanoid females, for a 9:6 ratio. Discounting Jax it's 8:6
Freljord's got 12 champions and I know the ratio by heart: 8:4 in male favour
The specifics are six human males, two human females, one troll male, one ursine male, one iceborn female and one unsexed entity that identifies as female (she's ice. I count that as unsexed). An interesting note I like about Freljord is despite the disparity in numbers in the lore Freljord's female cast are almost all the "main characters" of the region and are also the most powerful characters in the area, either through their political standing or their magical abilities.
--
Bilgewater's repped by only five champions (eight if you count Nami, Nautilus and Tahm Kench)
This makes for three human males, one human female and one "whatever the fuck Fizz is" male, for a 4:1 ratio in male favour.
If we include 
the ratio goes up to 6:2 with a male favour still.
I can keep going like this but I feel like you get the general gist. One thing I actually wonder about sometimes is these ratios in a racial sense, and by that I mean Runeterra's sentient species (the races). Runeterra is known to be inhabited by the following races:
- Ascendants
- Brackern (presumably they're still around)
- Celestial Entities (does this even count? I dunno)
- Darkin
- Demons
- Frozen Watchers
- Humans
- Iceborn
- Marai
- Trolls
- Ursine
- Voidborn (whom are of varying species)
- Yordles
- Whatever the fuck Fizz's people are called
- Whatever the fuck Morgana and Kayle's people are called and don't you say angel or I'll rip your arms off
Of these groups the vast majority are represented in game by only a single individual, with only humans, yordles, voidborn, ascendants, celestial entities and "whatever the fuck Morgana and Kayle's people are called" having multiple representatives of their kind.
Of these races only seven have a female representing them (humans, yordles, voidborn, celestials, M&K's people, Marai and Iceborn), only one of these races isn't playable and only three of them actually get new champions added to their ranks: humans, yordles and voidborn. That last point actually changed this year when Bard became the second celestial being to come to the game, although I'm still wondering if celestial beings can be counted as a "race" so to speak.
I went on a tangent and rambled for a long sodding time, but eh, whatever. TL;DR there's stuff. Go read it.
males 
- - 9 champs, 8:1 ratio of male and female.
-- 8 champs, 7:1 ratio(idk if ascended counts for unsexed for obvious reasons)
- -3 champs, 2:1, females to males
- -3 champs, 2:1, females to males
- -Could be more female
is also part of the Piltover champion pool according to the website.
