How would you translate this?

When I first came to Germany and was asked to translate a letter into English, I came across the German word beziehungsweise or the short form bzw. and had absolutely no idea how to translate it in an adequate way.

So let’s form a sentence with the German word:

Martin und Lisa sind seit 6 beziehungsweise 9 Jahren bei der Firma.

This means that Martin has been working in the company for six years and Lisa for nine.

So we could say:

Martin and Lisa have been working in the company for six and nine years, respectively. 

But I still prefer my first sentence! It should be clear for everybody!