Probably my calculator went wrong and also I didn't use compound.
The 13 days was the calendar days and that is the time that my fund was blocked.
After using compound, the result is not bad at all, actually it is very encouraging (worry it is too encouraging).
Should I quit my job now and devote in developing my signal detection program? :) I am sure it is more fun than TDF ... :)
Thanks,
Gu-shi