past tense - It's been a long time since I (went/have been) to Canada

It's been a long time since I went to Canada

Does the above sentence mean: since first or last went to Canada?

When you as a native speaker hear the above and below sentences, could you give me probabilities (by a sample of number of visits ) on the difference between those two sentences? This is of course if the first sentence has the meaning: first went to Canada

It's been a long time since I have been to Canada

If you feel it is better to change a long time into e.g. 5 years to make your answer clearer, then please do so.

Answer

It's been a long time since I went to Canada.

To me, the above sentence is ideal only in cases where there is only one visit to Canada. In that sense, it would be both a first and the last (most recent) visit. That said, it's a valid construction in a situation where multiple visits had occurred, but in these cases I’d argue for:

It's been a long time since I have been to Canada.

The way I figure it, the statement above has two main pieces of information:

1. 
   

   I have been to Canada (at least once; possibly multiple times)

   
   



2. 
   

   It has been a long time since then (since my last visit)

   
   

Broken down the same way, the first sentence has these two main pieces of information:

1. I went to Canada (most likely just once)


2. It's been a long time since then (since my one and only visit)

So it comes down to what you want to say. This might be the situation:

1. I went to Canada throughout my teens


2. It's been a long time since then

You could make an argument for either option in this case, but I maintain that the second sentence would more clearly indicate multiple visits.