Nonregular workers made up a record-high 38.2 percent of the workforce last year, topping the 20 million mark for the first time, a government survey has revealed.

The workers, who include part-time and contract employees, totaled 20.42 million, up 1.52 million from the previous survey in 2007, the data released Friday by the Internal Affairs and Communications Ministry said.

The ratio of nonregular employees has jumped 16.5 points over the past 20 years, reflecting a significant shift in corporate working conditions in which jobs were predominately held by full-time workers.

The quinquennial survey also found that among the nonregular workers, 22.1 percent were male and 57.5 percent female.

Meanwhile, the number of regular workers who switched to nonregular employment climbed 3.7 points from the 2007 survey to a hefty 40.3 percent. By contrast, the proportion of employees who shifted to regular from nonregular work dipped 2.3 points to 24.2 percent.

The survey covered around 1 million people, including foreign nationals, aged 15 or older.