More cynically, just block everything from China and you've covered 95% of the attacks (based on the stats reported in the article).
The United States is the #2 top source of cyber attacks, accounting for about 10% of all malicious traffic in the world and with 17.12% of cyber attacks initiated from there.
What you need to look at is how much of the traffic that hits your servers specifically is malicious relative to the amount of traffic that is bringing you revenue. Then you decide what countries to block.