According to a disclosure filed this week, Amazon paid less than £4.6 million on taxes in the United Kingdom last year — dropping by almost half from 2016 — even as profits in the country tripled.

Amazon managed to slice its corporate tax payment nearly in half in the United Kingdom last year, according to documents filed this week. In 2016, Amazon paid £7.4 million in British taxes. In 2017, the company paid only £4.6 million. In the same time, the company’s profits jumped from £24.3 million to almost £72.4 million.

As the corporate level, Amazon claims to have a net income of $2.5 billion. Additionally, the company has now posted $1 billion in profits for three consecutive quarters. Because of this, many still believe that Amazon should be paying more in corporate taxes.

The Tax Justice Network, an anti-tax avoidance advocacy group based in the U.K., said that Amazon’s tax bill is an “insult,” especially given their growth.

“It clearly shows that our global tax system is fundamentally broken and needs urgently fundamental reform,” the group said in a comment to CNBC. “Otherwise, small and medium enterprises will be ruined at the expense of global players who are most aggressive in pushing down their tax rates and controlling ever more market share.”

An Amazon spokesperson defended their lower tax payment, arguing that taxation is based on profit, not revenue. According to the spokesperson, the amount that Amazon paid is fair given their level of profit between 2016 and 2017. “Corporation tax is based on profits, not revenues, and our profits have remained low given retail is a highly-competitive, low margin business and our continued heavy investment.”