Hi Shashi,
Life span of dogs is around 15 years (+- 4 years). The age varies with the way dog is kept. Nicely kept dogs can live up to 15+ years.
Talking specifically about breeds and age, I must say that the long nosed breeds live longer than short nosed (Pug, Boxer etc) breeds. I would consider Spitz (Cross Breed) as long nosed and so, it shall live live more than 12 years.