President Donald Trump’s efforts to bring down prices of prescription drugs have been a resounding success.

“Starting next year, American drug prices will come down fast and furious and will soon be among the lowest in the developed world,” President Trump promised in December.

Prescription drug prices fell 0.8 percent in July, a steep monthly decline, the government’s consumer price index showed Wednesday.

This continued a pattern seen through most of this year. Prices have fallen in five of the last seven months and have not increased at all this year. Compared to one year ago, prescription drug prices are down 3.1 percent.

Here’s how drug prices have changed this year.

• January: unchanged
• February: −0.2 percent
• March: −1.5 percent
• April: unchanged
• May: −0.9 percent
• June: −0.1 percent
• July: −0.8 percent

As Renaissance Macro pointed out, over the last six months, prescription drug prices have fallen at an annualized rate of 6.6 percent, the sharpest drop on record.

Non-prescription medicine prices also fell in July, declining 0.3 percent. In June, they climbed 0.1 percent after falling 0.8 percent in May. Compared with a year ago, prices are down 1.7 percent.