Citizen BM7170-53L

Hey. Does anyone know when this watch was released ? I've been doing a bit of net snooping and the earliest I've come up with is 2012. Here's the thing though, I think I've owned this watch from new for well over 15 years. Perhaps even 20. Time flies though, and I'm probably mistaken.

It's the oldest watch in my collection, and even though it looks like it's been through the wars in the pics, it still looks great, and works perfectly 馃グ聽

Thanks in advance if anyone comes up with the release date馃憤馃徎