057:
EDIT: The sealed pack below indeed came from late 2004, but the sticker itself was likely first released in October 2003, as can be seen in @rainbow’s post below. Thanks for the correction. 
The release year of the Topsun Advanced Generations sticker set is likely late 2004. Although the set was gen 3 (additionally proved by Starmie being number 144, which corresponds to its Hoenn index number), the packs these yellow-bordered stickers came in had a gen 4 Pokémon at the back: Munchlax, which was debuted in the seventh Pokémon Movie: Destiny Deoxys, released in Japan on July 17th, 2004:
Source: This IG post of @nidokingdom.
Greetz,
Quuador