I have decided to compile the total number of different types of each generation, and then overall. If a Pokemon has two types I counted each type as a half. (e.g. Charmeleon would be 1 fire, Charizard would be 0.5 fire and 0.5 flying). Also, Burmy and Wormadam were just counted as pure bug each, because 0.25 of each Bug/Steel/Grass/Ground would just corrupt the entire system.
Here are my results:
GENERATION I
As a number:
1. Water (25)
2. Poison (21.5)
3. Normal (20)
4. Fire (11)
4. Psychic (11)
6. Ground (10)
7. Flying (9)
8. Fighting (8)
9. Bug (7.5)
9. Electric (7.5)
9. Grass (7.5)
12. Rock (5.5)
13. Dragon (2.5)
13. Ice (2.5)
15. Ghost (1.5)
16. Steel (1)
17. Dark (0)
Total: 151
As a percentage:
16.5% Water
14.2% Poison
13.2% Normal
7.3% Fire
7.3% Psychic
6.6% Ground
5.9% Flying
5.3% Fighting
5.0% Bug
5.0% Electric
5.0% Grass
3.6% Rock
1.7% Dragon
1.7% Ice
1.1% Ghost
0.6% Steel
0.0% Dark
GENERATION II
As a number:
1. Normal (18)
2. Water (13.5)
3. Flying (9.5)
4. Fire (8)
4. Grass (8)
6. Electric (6.5)
6. Psychic (6.5)
8. Ground (6)
9. Bug (5.5)
10. Rock (4.5)
11. Dark (3.5)
12. Fighting (2.5)
12. Ice (2.5)
14. Poison (2)
14. Steel (2)
16. Ghost (1)
17. Dragon (0.5)
Total: 100
As a percentage:
18.0% Normal
13.5% Water
9.5% Flying
8.0% Fire
8.0% Grass
6.5% Electric
6.5% Psychic
6.0% Ground
5.5% Bug
4.5% Rock
3.5% Dark
2.5% Fighting
2.5% Ice
2.0% Poison
2.0% Steel
1.0% Ghost
0.5% Dragon
GENERATION III
As a number:
1. Water (19.5)
2. Normal (16.5)
3. Psychic (14)
4. Grass (11.5)
5. Bug (9.5)
6. Ground (7.5)
7. Rock (7)
8. Dark (6.5)
9. Flying (6)
10. Dragon (5.5)
10. Steel (5.5)
12. Ghost (5)
13. Fighting (4.5)
13. Ice (4.5)
15. Electric (4)
15. Fire (4)
15. Poison (4)
Total: 135
As a percentage:
14.4% Water
12.3% Normal
10.4% Psychic
8.5% Grass
7.1% Bug
5.5% Ground
5.3% Rock
4.9% Dark
4.4% Flying
4.1% Dragon
4.1% Steel
3.7% Ghost
3.3% Fighting
3.3% Ice
2.9% Electric
2.9% Fire
2.9% Poison
GENERATION IV
As a number:
1. Normal (15)
2. Water (11.5)
3. Grass (10.5)
4. Psychic (7.5)
5. Flying (7)
6. Bug (6.5)
7. Electric (6)
7. Ground (6)
9. Ghost (5)
9. Rock (5)
9. Steel (5)
12. Dark (4)
12. Fighting (4)
12. Poison (4)
15. Fire (3.5)
15. Ice (3.5)
17. Dragon (3)
Total: 107
As a percentage:
14.0% Normal
10.7% Water
9.8% Grass
7.0% Psychic
6.4% Flying
6.2% Bug
5.6% Electric
5.6% Ground
4.7% Ghost
4.7% Rock
4.7% Steel
3.8% Dark
3.8% Fighting
3.8% Poison
3.2% Fire
3.2% Ice
2.8% Dragon
OVERALL
As a number:
1. Normal (69.5)
1. Water (69.5)
3. Psychic (39)
4. Grass (37.5)
5. Flying (31.5)
5. Poison (31.5)
7. Ground (29.5)
8. Bug (29)
9. Fire (26.5)
10. Electric (24)
11. Rock (22)
12. Fighting (19)
13. Dark (14)
14. Steel (13.5)
15. Ice (13)
16. Ghost (12.5)
17. Dragon (11.5)
Total: 493
As a percentage:
14.1% Normal
14.1% Water
7.9% Psychic
7.7% Grass
6.3% Flying
6.3% Poison
5.9% Ground
5.8% Bug
5.4% Fire
4.8% Electric
4.4% Rock
3.9% Fighting
3.0% Dark
2.8% Steel
2.7% Ice
2.6% Ghost
2.4% Dragon
Here are my results:
GENERATION I
As a number:
1. Water (25)
2. Poison (21.5)
3. Normal (20)
4. Fire (11)
4. Psychic (11)
6. Ground (10)
7. Flying (9)
8. Fighting (8)
9. Bug (7.5)
9. Electric (7.5)
9. Grass (7.5)
12. Rock (5.5)
13. Dragon (2.5)
13. Ice (2.5)
15. Ghost (1.5)
16. Steel (1)
17. Dark (0)
Total: 151
As a percentage:
16.5% Water
14.2% Poison
13.2% Normal
7.3% Fire
7.3% Psychic
6.6% Ground
5.9% Flying
5.3% Fighting
5.0% Bug
5.0% Electric
5.0% Grass
3.6% Rock
1.7% Dragon
1.7% Ice
1.1% Ghost
0.6% Steel
0.0% Dark
GENERATION II
As a number:
1. Normal (18)
2. Water (13.5)
3. Flying (9.5)
4. Fire (8)
4. Grass (8)
6. Electric (6.5)
6. Psychic (6.5)
8. Ground (6)
9. Bug (5.5)
10. Rock (4.5)
11. Dark (3.5)
12. Fighting (2.5)
12. Ice (2.5)
14. Poison (2)
14. Steel (2)
16. Ghost (1)
17. Dragon (0.5)
Total: 100
As a percentage:
18.0% Normal
13.5% Water
9.5% Flying
8.0% Fire
8.0% Grass
6.5% Electric
6.5% Psychic
6.0% Ground
5.5% Bug
4.5% Rock
3.5% Dark
2.5% Fighting
2.5% Ice
2.0% Poison
2.0% Steel
1.0% Ghost
0.5% Dragon
GENERATION III
As a number:
1. Water (19.5)
2. Normal (16.5)
3. Psychic (14)
4. Grass (11.5)
5. Bug (9.5)
6. Ground (7.5)
7. Rock (7)
8. Dark (6.5)
9. Flying (6)
10. Dragon (5.5)
10. Steel (5.5)
12. Ghost (5)
13. Fighting (4.5)
13. Ice (4.5)
15. Electric (4)
15. Fire (4)
15. Poison (4)
Total: 135
As a percentage:
14.4% Water
12.3% Normal
10.4% Psychic
8.5% Grass
7.1% Bug
5.5% Ground
5.3% Rock
4.9% Dark
4.4% Flying
4.1% Dragon
4.1% Steel
3.7% Ghost
3.3% Fighting
3.3% Ice
2.9% Electric
2.9% Fire
2.9% Poison
GENERATION IV
As a number:
1. Normal (15)
2. Water (11.5)
3. Grass (10.5)
4. Psychic (7.5)
5. Flying (7)
6. Bug (6.5)
7. Electric (6)
7. Ground (6)
9. Ghost (5)
9. Rock (5)
9. Steel (5)
12. Dark (4)
12. Fighting (4)
12. Poison (4)
15. Fire (3.5)
15. Ice (3.5)
17. Dragon (3)
Total: 107
As a percentage:
14.0% Normal
10.7% Water
9.8% Grass
7.0% Psychic
6.4% Flying
6.2% Bug
5.6% Electric
5.6% Ground
4.7% Ghost
4.7% Rock
4.7% Steel
3.8% Dark
3.8% Fighting
3.8% Poison
3.2% Fire
3.2% Ice
2.8% Dragon
OVERALL
As a number:
1. Normal (69.5)
1. Water (69.5)
3. Psychic (39)
4. Grass (37.5)
5. Flying (31.5)
5. Poison (31.5)
7. Ground (29.5)
8. Bug (29)
9. Fire (26.5)
10. Electric (24)
11. Rock (22)
12. Fighting (19)
13. Dark (14)
14. Steel (13.5)
15. Ice (13)
16. Ghost (12.5)
17. Dragon (11.5)
Total: 493
As a percentage:
14.1% Normal
14.1% Water
7.9% Psychic
7.7% Grass
6.3% Flying
6.3% Poison
5.9% Ground
5.8% Bug
5.4% Fire
4.8% Electric
4.4% Rock
3.9% Fighting
3.0% Dark
2.8% Steel
2.7% Ice
2.6% Ghost
2.4% Dragon