About 940-thousand people switched mobile carriers without changing their phone numbers last month in the aftermath of a massive data breach at SK Telecom(SKT). 

According to the Korea Telecommunications Operators Association on Monday, 933-thousand-509 subscribers to SKT, KT, LG Uplus and low-cost carriers switched mobile carriers in May without changing their phone numbers.

The May figure marks a 77 percent increase from some 526-thousand recorded in March, before the SKT hacking incident.

The figure is usually around 500-thousand, and this is the first time in five years it has exceeded 600-thousand. 

Of those who switched carriers in May, nearly 200-thousand moved from SKT to KT, in sharp contrast to the 30-thousand or 40-thousand that would normally have been expected in a single month.