The US last year slid down the rankings of a global corruption index as America’s system of checks and balances faced growing threats on Donald Trump’s watch, Transparency International said Tuesday.

The US lost four points to score 71 out of 100 on the watchdog’s 2018 Corruption Perceptions Index, sending the country tumbling out of the top 20 for the first time since 2011.

“The low score comes at a time when the US is experiencing threats to its system of checks and balances as well as an erosion of ethical norms at the highest levels of power,” TI said in its annual report.

The second year of Trump’s presidency was a turbulent one, ranging from damaging revelations in an investigation probing links between Trump’s 2016 campaign team and Russia, to his controversial backing for a Supreme Court nominee accused of sexual assault.

The US leader, who frequently rails against the media for writing “fake news,” was also dogged by accusations of nepotism and conflicts of interest.

Last month, Trump agreed to close his personal charity after the New York attorney general said it had acted “as little more than a checkbook to serve Mr. Trump’s business and political interests.”

Transparency International’s closely-watched index ranks 180 nations according to their perceived level of public sector corruption, where a score of zero means very corrupt and 100 signifies very clean.