A program written in C will execute faster if you run it multiple times, and slower if it has not been run recently. Presumably all of the benchmarks consist of many thousands of repetitions of the same process.
http://benchmarksgame.alioth.debian.org/u64q/program.php?tes...
The measurement shown is 21.54 secs.
The average JMH shows is 23.367 ± 0.062.