Magazine date:
Oct 2019 
After the Boeing 737 MAX was grounded [4], the American manufacturer conducted a global inspection of its aircrafts. On October 31, 2019, the aircraft manufacturer announced that it had discovered fork pickle cracks of about fifty 737 NG jets, that is 5% of the aircraft tested. Defective aircrafts are immediately kept on the ground for repair.
As a reminder, the 737 MAX crisis represents a financial disaster for Boeing that could amount to up to 20 billion USD.
* Pickle fork: part that connects the wings to the fuselage.