I hink 98 or 99, because Dex and Melvin got their pro cards around that time, and the NPc was still producing quality. Ronnie, Flex, Shawn, Chris, Kev, were last of the old guard and still in top form...by 2003-2004, it was the last of the Cretaceous Period--and Ronnie Coleman was King Rex (T Rex, but meant in a dominant awe inspiring way)....
The NPC has lost it's quality control and opted for dollar signs, thus leading to piss poor quality Pros. Sure there have been some moments of good quality Pros like Phil Heath and Richard Jones, but most of the guys getting their Pro Cards today would have been relegated to the lower rungs of the NPC back in 1996-99.