The Stockholm Convention has been successful in reducing the emission of regulated POPs since its enforcement. The emission levels of PCBs, for example, decreased by over 60% from 2001 to 2020, while dioxin levels also dropped by 50% from 2001 to 2020 (top of Figure ). This reduction is also noticeable as the number of registered patents for 17 dioxins, 12 PCBs and hexachlorobenzene (HCB) dropped since the Convention (bottom of Figure ).