They specifically look at the absolute change from the score last January. Biggest delta = DB of the year.

From the article:

“We calculate the DBMS of the year by subtracting the January 2024 from the January 2025 scores. We use the difference between each DBMS’s score, rather than a percentage growth, which would favor systems with lower popularity at the beginning of the year. The DMBS of the year is an illustration of how much each system increased in popularity during the year”

Because it's more about trends than current rankings.

From that site’s own info page: “The DB-Engines Ranking does not measure the number of installations of the systems, or their use within IT systems.”

Their methodology, even as stated, seems to be pretty flawed.