source = ([
{ year: 2020, month: "jan", total: 10 },
{ year: 2020, month: "feb", total: 20 },
{ year: 2019, month: "jan", total: 10 },
{ year: 2019, month: "feb", total: 7 },
{ year: 2018, month: "jan", total: 10 },
{ year: 2018, month: "feb", total: 5 }
])