From the existing records on rice tax in various provinces, it can be thought that after continuing such strict management system for nearly 30 years, the amount stored in fudoso corresponded with more than 30 years' rice tax income in the Tenpyo era (almost the same as the yearly crop yields).
こうした厳重な管理体制が約30年近く後天平年間田租収入の30年分余りの（田地からの年間収穫量とほぼ同一）の貯蔵が存在していたことが現存する各令制国の正税帳から推測できる。