Complex sentence: The Haydenettes were the 2010 national champions with a score of 231.14, the highest-ever posted to date at the U.S. Synchronized Skating Championships by nearly 18 points.
Split into simpler sentences: The Haydenettes were the 2010 national champions with a score of 231.14. This was the highest ever posted to date at the U.S. Synchronized Skating Championships by nearly 18 points.