Mean eccentricity of the asteroids in the parking zone, and the disk (within 100 au) as a function of time for the respective Oort clouds (inner and outer). Initially, all asteroids have relatively high eccentricity, but this rapidly drops in the first few tens of millions of years because of ejection by the planets. The Oort cloud population remains steady after about 100 Myr, whereas the more inner regions slowly converge to a similar eccentricity of ∼0.7.