I will answer that question.
It is the same tolerance level internationally: 0.05% for gas pumps. When the tolerance calculations are done, several factors come into play. There are financial factors, but there are also technical factors, because there is the matter of measurement uncertainty.
At a given time, it is all fine and well to have a little tolerance, but if people are not able to have measurement devices in order to do a good inspection, it is worthless. Technical uncertainty is taken into account as well as the financial impact.
In a nutshell, the 0.05% level is an international standard.