What Level Do Vaporeon Evolves In Pokemon Soul Silver?

Vaporeon does not evolve. Eevee is its base form. Its evolutions are:
 
Vaporeon  -  Use a Water Stone
Flareon - Use a Fire Stone
Jolteon - Use a Thunder Stone
Umbreon - Level it up while its happy in the night time
Espeon - Level it up while its happy in the day time
Glaceon - Level it up near the ice covered rock. (Google it for more info)
Leafeon - Level it up near the Moss covered rock. (Google it for more info)