From CQ Magazine:

The representative dealing with the most is Republican David Young of Iowa, who, according to an analysis by LegBranch, saw half his staff quit in 2017. That compared to a median House turnover rate last year of 17 percent, according to LegBranch, which is a joint project of New America and the R Street Institute,both think tanks. It relied on data compiled by LegiStorm, a company that tracks data on Congress using publicly available employment records.