Equids - Proportion of equids holding a passport

Percentage of registered alive equids with equine passports recorded on the AMD in Switzerland, Liechtenstein and abroad over time.随时间推移，瑞士、列支敦士登及境外地区内，在AMD中登记记录的、持有马护照（equine passport）的存活马科动物（equid）的占比。