May represented a best-ever daily selling rate for the certified pre-owned car business and year-to-date CPO sales have eclipsed the 1 million mark, according to Autodata Corp.

Through five months, there have been 1.1 million certified sales, which is 3.6 percent ahead of last year’s pace, the firm said in its data set released Wednesday.

May’s monthly sum was 221,732 certified units sold — a 4.6-percent year-over-year decrease — but with 24 selling days, the average of 9,239 CPO units sold per day represented an all-time record.

Speaking of records, Lexus had its best CPO sales month ever, Autodata said. It sold 8,924 certified vehicles in May, beating year-ago figures by 16 percent.

Lexus and its Asian-brand peers led the way in May, selling a combined 108,553 CPO vehicles, which was up 0.9 percent. Through five months of 2016, Asian brands have sold 526,413 certified units, which is up 9.2 percent.

May sales for the Big 3 dipped 7.7 percent at 75,404 CPO units sold, but year-to-date sales still remain ahead of last year’s, with 396,000 units sold (up 0.4 percent).

European brands moved 37,775 certified vehicles in May, which was down 12.7 percent. Year-to-date, they have sold 178,528 CPO units (down 3.9 percent).

Autodata notes that Volvo and Bentley figures (which are included in the European and overall totals) are estimates.