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 "<answer>one province to one affected county</answer>" basis. The plan spanned 3 years, and cost no less than one percent of the province or municipality's budget.
What is the basis for this plan?
one province to one affected county