Generally, patents filed since 1995 last for 20 years from the date that the drug was invented.

一般来说，自1995年以来申请的专利会从药物发明之日起持续20年。

We found that, on average, there are 125 patents filed on each medicine.

我们发现，平均而言，每种药物有 125 项专利申请。