I added a few more dates as proof.
let data = ["2018-1", "2018-5", "2018-11", "2018-2", "2018-10", "2018-12", "2017-5", "2019-12"];
var result = data.sort((a, b) => {
var n1 = a.split("-");
var n2 = b.split("-");
n1 = parseInt(n1[0]) * 100 + parseInt(n1[1]);
n2 = parseInt(n2[0]) * 100 + parseInt(n2[1]);
return n1 - n2;
})
console.log(result);