Here’s a startling statistic: More than 47 million Americans quit their jobs last year, according to the U.S. Bureau of Labor Statistics. But why? What has led to what many are calling the Great Resignation?

Real estate company Clever has come up with some answers. The company surveyed 1,000 people who resigned from a job since January of 2021. Clever found that everything from the COVID-19 pandemic to bad company culture inspired these respondents to make a job change.

According to Clever, 31% of survey respondents said they left their jobs because of toxic company culture. An additional 30% said they left because they didn’t agree with their company’s response to the COVID-19 pandemic. And another 30% said they moved on because they had changed their career goals.

These employees often made their decisions to leave quickly. Clever found that 60% of respondents considered leaving their jobs for just one month before they resigned. And one in four respondents debated leaving for one week or less before quitting.

November of last year saw an especially high number of resignations. The Bureau of Labor Statistics said that a record-setting 4.527 million workers quit their jobs in that month.

Of course, the pandemic played a big role in these resignations. A total of 80% of respondents to Clever’s survey said that the pandemic influenced their decision to quit. And of those employees who said that they quit because of the pandemic, 41% did so because they said their employer didn’t enforce health and safety protocols while 28% said they didn’t want to follow their employer’s COVID-19 protocols.

Respondents weren’t shy about leaving quickly, either. Clever found that 49% of respondents gave their employers one-week notice or less when they quit. One in four gave no notice at all.

Employers struggled to convince respondents to change their minds. Clever found that 80% of respondents received a counteroffer from their employer when they resigned but still decided to leave.