It's in reverse: Russia has a 1 year long mandatory military service for men aged 18-26 inclusively; roughly 30% serve it, guess which part of the IQ curve doesn't want to spend a year painting grass to green during winter.

The first tier of reserves are anyone who did it and are under 35, as well as officers under 45-60 dependent on rank, the other 2 tiers are either unfit or older. The average Ivan in the first class reserve is pro-government, poor and without higher education.