▁was ▁ 9 ▁billion ▁cub ic ▁meters . ▁In ▁the ▁years ▁ 1 9 9 2 – 1 9 9 3 ▁the ▁census ▁of ▁ 2 8 0 5 4 ▁q an ats ▁showed ▁a ▁total ▁dis charge ▁of ▁ 1 0 ▁billion ▁cub ic ▁meters . ▁ 1 0 ▁years ▁later ▁in ▁ 2 0 0 2 – 2 0 0 3 ▁the ▁number ▁of ▁the ▁q an ats ▁was ▁reported ▁as ▁ 3 3 6 9 1 ▁with ▁a ▁total ▁dis charge ▁of ▁ 8 ▁billion ▁cub ic ▁meters . ▁ ▁In ▁the ▁year ▁ 2 0 0 0 , ▁holding ▁the ▁International ▁Conference ▁on ▁Q an ats ▁in ▁Y az d ▁drew ▁a ▁lot ▁of ▁attention ▁to ▁the ▁q an ats . ▁In ▁ 2 0 0 5 ▁the ▁Iran ian ▁government ▁and ▁UN ES CO ▁signed ▁an ▁agreement ▁to ▁set ▁up ▁the ▁International ▁Center ▁on ▁Q an ats ▁and ▁Historic ▁H yd ra ul ic ▁Struct ures ▁( IC Q HS ) ▁under ▁the ▁aus p ices ▁of ▁UN ES CO . ▁The ▁main ▁mission ▁of ▁this ▁center ▁is ▁the ▁recognition , ▁transfer ▁of ▁knowledge ▁and ▁experiences , ▁promotion ▁of ▁information ▁and ▁capac ities ▁with ▁regard ▁to ▁all ▁the ▁aspects ▁of ▁q an at ▁technology ▁and ▁related ▁historic ▁hyd ra ul ic ▁structures . ▁This ▁mission ▁a ims ▁to ▁ful fill ▁sust ain able ▁development ▁of ▁water ▁resources ▁and ▁the ▁application ▁of ▁the ▁outcome ▁of ▁the ▁activities ▁in ▁order ▁to ▁preserve ▁historical ▁and ▁cultural ▁values ▁as ▁well ▁as ▁the