The number of migrants apprehended at the southwest border dropped for a sixth straight month, with 64,000 people apprehended or turned away at border crossings in August, according to Trump administration officials. Of those, 55% were families and unaccompanied minors.

While last month’s numbers represent a 56% drop from their peak in May, and a 22% drop since July, apprehensions are still at “crisis levels,” officials said, with August totals higher than any August since 2007.

The administration has credited the decrease to policies put in place since June such as the Migrant Protection Protocols or “Remain in Mexico” program, which has sent more than 43,000 migrants back across the Rio Grande to await the adjudication of their immigration cases in Mexico. Officials have also cited increased collaboration with Mexico, which has mobilized 25,000 National Guard troops to secure the southern and northern borders, and the so-called Northern Triangle countries of Guatemala, Honduras, and El Salvador.

Personnel from U.S. Customs and Border Protection and Border Patrol, among other U.S. agencies, have deployed to the Northern Triangle countries in recent months to train and support law enforcement agencies in those countries in their efforts to disrupt smuggling organizations and tighten immigration controls at checkpoints, airports, and border crossings.

Despite these efforts, significant numbers of migrants continue to travel north seeking to enter the United States. Although the majority are families and minors, a significant number are single adults and generally attempt to evade U.S. authorities. In August, CBP apprehended nearly 29,000 single adults, an increase of more than 5,000 from July. Since the beginning of the fiscal year, officials say they are aware of at least 130,000 migrants who successfully evaded U.S. authorities at the border and entered the country illegally.

It remains to be seen whether border crossings will continue to decrease as summer temperatures ease off. Typically, apprehension totals drop in June and July as it becomes more difficult and dangerous to cross because of the heat. In recent years, the numbers have tended to increase from July to August, making this month a historic outlier. The past five years, however, have all seen multiple months with historic outliers, which means it is probably too soon to claim, as Politico’s Ted Hesson did recently, that the Trump administration’s policies to reduce illegal immigration along the border are going to work in the long term.