Wow, it's been 10 years since the last one. I had just come to Japan to teach, and hardly knew the people from my dojo. It really brings back memories.
Do you mean the last IAF Congress, or the last IAF Congress in Tanabe?
The last IAF Congress was held in Tokyo in 2004, but the last IAF Congress to be held in Tanabe was the 5th Congress, which took place in August, 1988.