I've only had my car a short time, but my 98 clock was worthless - couldn't read it day or night, bad design. I just put in a clock with numerals that I purchased from ebay and the difference is amazing. I can now read it easily day and night. The clock without the numbers should never have happened.
I don't know years of numerical clock, but I highly recommend switching to one.

 

I swapped the opposite way, replacing the white marked clock with numbers, with one without numbers and silver markings. It's purely cosmetic... because you're right, it's almost impossible to read!

There is a secret third option... there is a white faced one used in Aston Martins that's exactly the same.

Somewhere around here is another thread with pictures of all three... google might have it too