Milon has fifteen years of typing experience behind him therefore , if you are looking for an efficient typist to enter you data into the new system, you need look no further . The speaker assumes that

Milon is an outstandingly fast and accurate typist

The type of typing required for the new system is identical to what milon has been doing .

Milon's job profile is the best that the new employer is going to get

Fifteen years of practice ensures typing efficiency