Derived age-velocity dispersions for three different 2-kpc-wide annuli (the Sun is located at R_⊙ = 8.249 kpc). The width of the lines corresponds to the statistical uncertainty on the dispersion $(\sigma /\sqrt{2(n-1)}$, with n the number of stars in a considered bin). Dashed lines are functions in the form of σ_V = β · τ^k, with adopted values for σ_R, σ_ϕ, and σ_Z of β = [27,18,10] and k = [0.31,0.34,0.47]. Only stars up to 1 kpc from the plane are considered.