Age of Maturity in the Core Four

Or perhaps I should state that as age of adulthood since some peeps never mature. In humans its run the gammut of late teens to twenty. Industrialized heavy population world probably tend toward the older end of that range while out post and light population world could tend toward lower numbers. I was just wondering what the age ranges should be for the core four? My first knee jerk reaction is vrusk must mature fairly fast. For yazirians it could be less then for humanity and Drals could be anything from a little less then humans to a little more. Comments?