I wish benchmarks with sample means in the tens of nanoseconds weren't reported and compared by the arithmetic mean. These are not normal distributions and a 10% improvement could just mean you improved the 99% percentile, which is quite typical in my experience given how skewed the distributions tend to be.
Many of the benchmarks are using BenchmarkDotNet, so consider reporting this to them: https://github.com/dotnet/BenchmarkDotNet/ .
[0] https://devblogs.microsoft.com/dotnet/performance_improvemen...
edit: meant "excluding", not "including"