Need help to display sequential numbers in a text box

Hi all,
This might be a simple requirement.
I have a textbox and my requirement is, “Display numbers in that Textbox like a digital meter running from 30000 to 100000 for about 15 seconds and stop”.
I have created a Keyframe for 10 seconds(around 240 frames) and in action frame, tried using some loops/user defined Wait functions, but didnt worked for me.

Any sort of hints in resolving this are much appreciated.