Correlation of ratings for different platforms (7th generation)

I've done a small research on the ESRB, PEGI and USK ratings. I took data from corresponding sites www.esrb.org, www.pegi.info and www.usk.de.

1. Some data
*There are 1505 games for Wii, 1461 for DS, 816 for PS3, 798 for PSP and 1013 for Xbox on the ESRB website.
*There are 638 games for Wii, 1206 for DS, 335 for PS3, 474 for PSP and 542 for Xbox on the PEGI website. I used France as the country instead of UK, because 18+ games are treated differently in the UK.
*There are 1239 games for Wii, 1667 for DS, 527 for PS3, 657 for PSP and 855 for Xbox on the USK website.

Results for ESRB
Rat| Wii| DS| PS3| PSP| Xbox360
"EC"| 4| 4| 0| 0| 0
"E"| 947| 1071| 320| 347| 367
"E10"| 282| 246| 97| 122| 152
"T"| 233| 130| 248| 265| 297
"M"| 39| 10| 151| 64| 197
"AO"| 0| 0| 0| 0| 0
Total| 1505| 1461| 816| 798| 1013

Results for PEGI (France)
Rat| Wii| DS| PS3| PSP| Xbox360
"3+"| 359| 831| 74| 192| 168
"7+"| 111| 199| 25| 58| 44
"12+"| 113| 150| 79| 143| 126
"16+"| 39| 18| 86| 55| 128
"18+"| 13| 6| 71| 26| 76
Total| 638| 1206| 335| 474| 542

Results for USK (Germany)
Rat| Wii| DS| PS3| PSP| Xbox360
"0"| 707| 1197| 165| 262| 255
"6"| 282| 297| 68| 113| 130
"12"| 190| 138| 124| 186| 222
"16"| 38| 13| 77| 71| 120
"18"| 21| 10| 93| 24| 125
Total*| 1239| 1667| 527| 657| 855

*(Total number may be higher because of so called "indiziert" games, which didn't receive any rating).

You can see, that the number of PEGI rated games is somewhat smaller than of ESRB and even USK.

2. Goal
What I wanted to know is how many games for kids are there. It's a hard task to decide, which games are "for kids", so I decided to take the following formulas:

(1)
ESRB : ("EC"+"E"+"E10") / ("T"+"M")
PEGI : ("3"+"7"+"12") / ("16"+"18")
USK : ("0"+"6"+"12") / ("16"+"18")

And thus to calculate the correlation of these rating for Wii, DS, PS3, PSP and Xbox360.

3. Results

(2)
ESRB:
For Wii it was 4.53
For DS it was 9.44
For PS3 it was 1.05
For PSP it was 1.43
For Xbox360 it was 1.05

Which means, that for every (T or M) game on Wii there are 4.53 games with (EC or E or E10) rating.

Next, PEGI for games released in France:

(3)
For Wii: 11.21
For DS: 49.17
For PS3: 1.13
For PSP: 4.85
For Xbox360: 1.66

And at last the data from the USK (Germany).

(4)
For Wii: 19.98
For DS: 70.96
For PS3: 2.1
For PSP: 5.91
For Xbox360: 2.48

4. Cumulative results for manufacturers
For the 7th generation (Wii, DS, PS3, PSP, Xbox360). The formulas from (1), but this time an average for consoles for manufacturers.

ESRB:
Nintendo: 13.97
Sony: 2.47
Microsoft: 1.05

PEGI:
Nintendo: 30.19
Sony: 2.99
Microsoft: 1.66

USK:
Nintendo: 45.47
Sony: 4.0
Microsoft: 2.48

5. Conclusion

With a big breakdown, the most "teen/adult" console is Xbox360, then PS3, then PSP (more for teens), then Wii and at last, with the biggest number of EC,E and E10 titles - Nintendo DS.