Due to the limited numbers of trade activities, they remained as income of a temporary nature, but it is said that there were cases where income from a single trade was as great as the other tax income of several years.
貿易の回数が限られていたために臨時収入的なものに留まったが、1回の貿易で他の税収の数年分の収益を挙げる事もあったとされている。