number formatter prefix for legend

[flaming-cl]

hey, would you please let us know how to dynamically add number formatter prefix for the legend values? assume my values are

USD $1,000, GBP £2,000, EUR €3,000

data: [
            { currency: "$", country: 'U', sales: 1000 },
            { currency: "£", country: 'G', sales: 2000 }, 
            { country: '€', country: 'E', sales: 3000 }
          ]