[susan53]

Sorry, but I diosagree. Perfect aspect never tells us anything about any time after the reference point. - so in 69 up to and including the present. But whether the event continues afterwards or not can only be established by the context, not by the verb itself. For example :

I've lived here for 40 years - This could be said in a context where the speaker's possessions were all packed up in a delivery van, she'd locked the front door and was out of the house for ever : I've lived here for 40 years. I'm really sad to think I'll never see the place again. Or could be followed by a statement indicating the continuation of the event : I've lived here for 40 years, and I doubt if I'll ever move again now.

Similarly, I've been waitng for thirty minutes! could be said when the person you're waiting for has just arrived (so the action of waiting has finished). : I've been waiting for 30 minutes! Why didn't you phone me? or when the action was going to continue : I've been waiting for 30 minutes and he still hasn't arrived. I'll give him 10 minutes more, and then i'm going.

But in all cases, it's the context which tells you whether or not the action will continue, not the verb form itself.

In the case of Zach has known Mike for about a year, the situation is slightly different. The idea of continuation is in the lexical item "know" rather than the context. Once you "know" something, it's generally presumed to be permanent. However, you could still think of a context where the event is not seen as continuing : Zach has known Mike for about a year, but since he got that bump on the head last week, he no longer recognises him.

So the verb form tells us that the event happened before, and possibly continues up to, the reference point (here the moment of speaking). But whether it continues afterwards or not depends entirely on other factors and is not inherent in the verb form at all.