Table:
text: Renewable energy in Spain
Production
Renewable Electricity in Spain (GWh, 2006 data)
Autonomous_Community Hydroelectric_power Wind_power Solar_power Biomass_power Solid_waste_power Total_Renewable_Generation Total_Electricity_Demand _Renewable_of_Total_Electricity_Demand
Castile and León 6960 3840 14 274 87 11175 15793 70.8%
Galicia 7561 5970 1 242 317 14091 20279 69.5%
La Rioja 124 897 1 3 2 1027 1860 55.2%
Aragón 3073 3342 1 63 8 6487 11885 54.6%
Navarre 379 2248 28 269 0 2924 5401 54.1%
Extremadura 2244 0 1 0 0 2245 5076 44.2%
Castile-La Mancha 710 3935 8 99 34 4786 12686 37.7%
Asturias 1680 357 0 221 400 2658 12391 21.5%
Cantabria 875 0 0 11 41 927 5693 16.3%
Catalonia 3223 301 7 77 241 3849 48498 7.9%

Question: What is the lowest numbered hydro if the renewable energy demand is 21.5% in renewable energy in Spain?