I have been using the solution for 20 years.

I've been working with the solution for four years.

We've been using the solution for three or four years, however, it may have been a bit longer.

I have been using the solution for four years.

I've been using the solution for many years. I don't know the exact number, however, I can safely say it's been more than five.

I've been using this solution for many years. 

I've been using the solution for ten years.

I have been using this solution for about a year and a half.

We are using the latest version.

Over seven years.

I've been using the solution for about ten years.

I have only been using SAS Enterprise Miner for a short time.