Single vs Double quote

JavaScript

var date1 = new Date();
var time_start = date1.getTime();
var txt;
for (var i = 0; i < 900000000; i++) {
    txt = 'Lorem "ipsum" te vim scripta pertinax';
}
var date2 = new Date();
var time_end = date2.getTime();

var time = time_end - time_start;
document.write('single quote: ' + time + 'ms');

date1 = new Date();
time_start = date1.getTime();
for (i = 0; i < 900000000; i++) {
    txt = "Lorem 'ipsum' te vim scripta pertinax";
}
date2 = new Date();
time_end = date2.getTime();

time = time_end - time_start;
document.write('<br/>double quote: ' + time + 'ms');