The number of migrants crossing the U.S. southern border illegally in President Trump’s first full month in office plunged to a level not seen in at least 25 years, according to preliminary government data obtained by CBS News.

Last month, Border Patrol recorded about 8,450 apprehensions of migrants who crossed into the country unlawfully between official entry points along the U.S.-Mexico border, the statistics show.

On some days during a record spike in illegal crossings under the Biden administration, Border Patrol recorded more than 8,000 apprehensions in a single day.

February’s total, which could be adjusted when the government officially publishes the statistics, would be the lowest monthly apprehensions tally recorded by Border Patrol since at least fiscal year 2000, the last period with public monthly data. The final tallies usually don’t deviate much from the preliminary figures.

Over the past 25 years, the only time monthly apprehensions came close to the level recorded in February was in April 2017, when Border Patrol apprehended 11,000 migrants at the southwest border, agency data show.