Diminishing Returns

The principle of Diminishing Returns discourages spending points in specific stat/skill to maximize it, each next point spent returns slightly less stat modifier:

Complete Table of values:
http://videogamedesign.wikidot.com/table:diminishing-returns

Short Example:
//for(i=1,r=0.99,percent=1.0;i<SkillLevel;i++){percent+=Math.pow(r,i);}
//percent
Formula for next increase is +0.99^lvl
Example Evade chance at skillLvl:
1=1.0%
2=1.0+0.99^1=1.99
3=1.99+0.99^2=2.9701
4=2.9701+0.99^3=3.9403989999999998
10=9.56179249911955
25=22.21786406008531
50=39.49939328624632
75=52.941335841434956
100=63.396765872677
125=71.52922267268036
150=77.85482127611378
200=86.60203251420367
250=91.89414838378167
300=95.09591059287125
400=98.20494467249529
500=99.34295169575842
600=99.75949907086877
750=99.9467406394111
1000=99.99568287525872
10000(max)=99.99999999999916

Inverse Diminishing Returns is the same Except it goes 100%to1%
100-0.99^lvl1-0.99^lvl2-…
//for(i=1,r=0.99,percent=100.0;i<SkillLevel;i++){percent-=Math.pow(r,i);}
0=100.0%(99% if you need to go to 0% instead of descent to 1%)
1=99.01%
2=98.02990000000001%
3=97.05960100000001
5=95.14801494010001
10=90.53382542587167
15=86.1457771094876
25=78.00431458051558
50=60.89560064661621
75=47.58807751697946
100=37.23720178604984
150=22.92372693664742
200=14.263987810938412
250=9.024793100056161
300=5.855048513057514
400=2.777104774229706
500=1.650477821199288
600=1.2380959198400405
700=1.0871508069868094
1000=1.0042739534939011