Don't depend on unordered object

Before, passing `range` as `{min: 1, max: 5, 25%: 2, 50%: 3}` and `{min: 1, 25%: 2, 50%: 3, max: 5}` would mean different results.
Because objects are not guaranteed to return keys in same order, 2 resulting number arrays need to be sorted.