Look in the source code for reward halving...
if(nHeight <= 525601)
nSubsidy = 16.39*COIN;
else if(nHeight <= 1051202)
nSubsidy = 16.63*COIN;
else if(nHeight <= 1576803)
nSubsidy = 16.88*COIN;
else if(nHeight <= 2102404)
nSubsidy = 17.14*COIN;
else if(nHeight <= 2628005)
nSubsidy = 17.39*COIN;
else if(nHeight <= 3153606)
nSubsidy = 17.65*COIN;
else if(nHeight <= 3679207)
nSubsidy = 17.92*COIN;
else if(nHeight <= 4204808)
nSubsidy = 9.09*COIN;
else if(nHeight <= 4730409)
nSubsidy = 9.16*COIN;
else if(nHeight <= 5256010)
nSubsidy = 9.23*COIN;
else if(nHeight <= 5781611)
nSubsidy = 9.30*COIN;
else if(nHeight <= 6307212)
nSubsidy = 9.37*COIN;
else if(nHeight <= 6832813)
nSubsidy = 9.44*COIN;
else if(nHeight <= 7358414)
nSubsidy = 9.51*COIN;
else if(nHeight <= 7884015)
nSubsidy = 9.58*COIN;
else if(nHeight <= 8409616)
nSubsidy = 9.65*COIN;
else if(nHeight <= 8935217)
nSubsidy = 9.73*COIN;
else if(nHeight <= 9460818)
nSubsidy = 9.80*COIN;
else if(nHeight <= 9986419)
nSubsidy = 9.87*COIN;
else if(nHeight <= 10512020)
nSubsidy = 9.95*COIN;
else if(nHeight <= 11037621)
nSubsidy = 10.02*COIN;
else if(nHeight <= 11563222)
nSubsidy = 10.10*COIN;
else if(nHeight <= 12088823)
nSubsidy = 10.17*COIN;
else if(nHeight <= 12614424)
nSubsidy = 10.25*COIN;
else if(nHeight <= 13140025)
nSubsidy = 10.33*COIN;
else if(nHeight <= 13665626)
nSubsidy = 10.40*COIN;
else if(nHeight <= 14191227)
nSubsidy = 10.48*COIN;
else if(nHeight <= 14716828)
nSubsidy = 10.56*COIN;
else if(nHeight <= 15242429)
nSubsidy = 10.64*COIN;
else if(nHeight <= 15768030)
nSubsidy = 10.72*COIN;
else if(nHeight <= 16293631)
nSubsidy = 10.80*COIN;
else if(nHeight <= 16819232)
nSubsidy = 10.88*COIN;
else if(nHeight <= 17344833)
nSubsidy = 10.96*COIN;
else if(nHeight <= 17870434)
nSubsidy = 11.04*COIN;
else if(nHeight <= 18396035)
nSubsidy = 11.13*COIN;
else if(nHeight <= 18921636)
nSubsidy = 11.21*COIN;
else if(nHeight <= 19447237)
nSubsidy = 11.29*COIN;
else if(nHeight <= 19972838)
nSubsidy = 11.38*COIN;
else if(nHeight <= 20498439)
nSubsidy = 11.46*COIN;
else if(nHeight <= 21024040)
nSubsidy = 11.55*COIN;
else if(nHeight <= 21549641)
nSubsidy = 11.64*COIN;
else if(nHeight <= 22075242)
nSubsidy = 11.72*COIN;
else if(nHeight <= 22600843)
nSubsidy = 11.82*COIN;
else if(nHeight <= 23126444)
nSubsidy = 11.90*COIN;
else if(nHeight <= 23652045)
nSubsidy = 11.99*COIN;
else if(nHeight <= 24177646)
nSubsidy = 12.08*COIN;
else
nSubsidy = 0;
LOL, where did they come up with this?