5 Fae ages like a human.
6-15 Fae ages slower. Equation: 5+(4*(X-5))
16-90 Fae ages even slower. Equation: 45+(5*(X-15))
91-120 Fae ages slowest. Equation: 420+(6*(X-90))
Every interval of 4 years denotes one year of aging for the Fae up until 45. After that point, it's at every interval of 5 years up until 420 years. If a Fae survives for longer, it is at every interval of 6 years.
Dwarves are simple little pricks that age 2:1. Two human years is one year of aging for a Dwarf.