I have used Microsoft DPM for nine years.

I have been using Microsoft DPM for approximately 10 years.

I have been using Microsoft DPM for about seven years.

I have been using this solution for almost six years.

We have the latest update.

I have been using this solution for approximately three years.

We've used the solution for six years at this point. It's been a while. 

I've been using the solution for about three years now.

I have been familiar with this solution for about six years.

I have been using Microsoft DPM for over three years.

I've been using the solution for almost a decade at this point. It's been about nine years. It's been a while.

I have been using this solution for six years.

I have been using Microsoft DPM for the past four years.

I've been using this solution for nine years. 

2.5 years.