Need some timeline help

[Canadian Atlantic Railway]

I am still fine tuning my era and and looking at setting my layout in the 1990-2000 range. When did the 50' hi-cube boxcars (Like this <!-- m --><a class="postlink" href="http://www.walthers.com/exec/productinfo/920-101708">http://www.walthers.com/exec/productinfo/920-101708</a><!-- m --> ) start to hit the rails? What year was yellow reflective tape made mandatory?