For use in Unity Asset Store sale page dev console

asset-sale.js

(async function get() {
	const publisher_id = 17505;
	const period = 12; //months

	function nextMon(current) {
		let mon = --current[1];
		let year = current[0];

		if (mon < 1) {
			year--;
			mon = 12;
		}

		return [year, mon];
	}

	const now = new Date();
	const from = [now.getFullYear(), now.getMonth() + 1];

	let current = from;

	let tsv = 'Month	Net\n';

	for (_ = 0; _ < period; _++) {
		const res = await fetch(
			`https://publisher.assetstore.unity3d.com/api/publisher-info/sales/${publisher_id}/${current[0] * 100 +
				current[1]}.json`
		);

		const data = await res.json();

		const net = data.result.map(s => parseFloat(s.net.slice(2))).reduce((sum, x) => (sum += x), 0);

		tsv += `${current[0]}-${current[1]}-01	${net}\n`;

		current = nextMon(current);
	}

	console.log('Done!');

	return tsv;
})().then(copy);

Usage:

1. Edit the 2 and 3 line to your publisher id and desired period. Save the script somewhere for later use.
2. Goto your sale page.
3. Open dev tool. F12 on chrome, google for your browser.
4. Paste the script to the console tab, Enter.
5. Wait till it say done. Result auto copied, just paste to excel.