[Mamady]

There are 2 major flaws in this experiment - both stem from this assumption

that the first couple of years of working for this company, are equivalent to the next 3 years.

This is obviously NOT correct.

1. The more you work with a codebase, the more you undestand its details and complexities - this alone should help you eliminate more bugs during developement.

2. You will have improved as a developer - meaning that the last 3 yeras in your life will have more experience and knowledge than the first 2.

As sad as I am at stating this fact... you cannot conclude that TDD actually works, because there are too many other variables involved.