What is the male:female ratio of gendered minifigures?
I found this interesting comment by J on a blog post about LEGO female oriented sets.

I did a count of male and female mini-figures by theme in the 2011
releases for which we have visual evidence. The modular house line
always tends to be more balanced so there’s still potential there but
the City theme is particularly bad this year. Here’s the results
(aliens/creatures are excluded except where male-female
differentiation exists:
Alien Abduction: 9 male, 1 female
Atlantis: 7 male, 1 female
Castle: 15 male, 1 female
City: 59 male, 5 female
Collectible Mini-Figures: 37 male, 10 female (omit 1 alien)
Creator: 2 male, 0 female
Dacta: 33 male, 19 female
Duplo: 16 male, 4 female
Harry Potter: 20 male, 3 female
Ninjago: 30 male, 3 female
Pharaoh’s Quest: 9 male, 1 female
Pirates of the Caribbean: 32 male, 4 female
Star Wars: 43 male, 7 female
Trains: 3 male, 0 female
TOTAL SYSTEM: 299 male, 55 female
TOTAL DUPLO: 16 male, 4 female
TOTAL: 315 male, 59 female
That’s greater than a 5:1 ratio and if you remove the Dacta and
Collectible Mini-figure sets from the equation, you get a pathetic 8:1
ratio (245 male, 30 female). I’ll say it again. If Lego wants girls to
take interest in their products, they should make a better effort to
include figures through which girls can identify.

The survey only takes into account 374 minifigures of the last year. It would be interesting to compare this data to minifigures released, 10, 20 and 30 years back to see how the gender ratio has changed.

Collectable Minifigures Series 1-9 &amp; Team GB
I've performed my own test, this time with Collectable Minifigures.
(Feel free to correct me on any of the ambiguous minifigures.)

Series 1: 10 male, 2 female, 4 ambiguous (Tribal Hunter, Circus
Clown, Robot, Demolition Dummy)
Series 2: 12 males, 3 females, 1 ambiguous (Mime)
Series 3: 11 male, 3 female, 2 ambiguous (Mummy, Space Alien)
Series 4: 13 male, 3 female
Series 5: 11 male, 4 female, 1 ambiguous (Small Clown)
Series 6: 9 male, 5 female, 2 ambiguous (Classic Alien, Clockwork
Robot)
Series 7: 11 male, 5 female
Series 8: 10 male, 5 female, 1 ambiguous (Evil Robot)
Series 9: 10 male, 5 female, 1 ambiguous (Battle Mech)
Team GB: 6 male, 3 female
TOTAL: 91 male, 30 female, 11 ambiguous
The ratio can roughly be simplified as 9:3:1 (m/f/a)

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Collectable Minifigures REVISITED (December 2014)
All the genders of ambiguous minifigures have been confirmed using the gender pronouns used on the official LEGO Minifigure minisite character page.

Series 1: 14 male, 2 female
Series 2: 13 males, 3 females
Series 3: 11 male, 3 female, 2 ambiguous (Mummy, Space Alien)
Series 4: 13 male, 3 female
Series 5: 12 male, 4 female
Series 6: 11 male, 5 female
Series 7: 11 male, 5 female
Series 8: 10 male, 5 female, 1 ambiguous (Evil Robot)
Series 9: 10 male, 5 female, 1 ambiguous (Battle Mech)
Series 10: 11 male, 5 female
Series 11: 10 male, 5 female,  ambiguous (Evil Mech)
Series 12: 11 male, 5 female
Team GB: 6 male, 3 female
The Simpsons: 13 male, 3 female
The LEGO Movie: 10 male, 6 female
TOTAL: 166 male, 22 female, 5 ambiguous

The share of unique female Collectable Minifigure from the main series have improved from 1/8 in Series 1 up to ~1/3 in Series 12. Collectable Minifigure that are not part of the standard series (Team GB, The Simpsons and The LEGO Movie) tend to vary.
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