2008 Sichuan earthquake:

In 2008, State Council established a counterpart support plan (《汶川地震灾后恢复重建对口支援方案》). The plan is to arrange 19 eastern and central province and municipalitie to help 18 counties, on "one province to one affected county" basis. The plan spanned 3 years, and cost no less than one percent of the province or municipality's budget.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". How long did the plan last?
3 years