ZSTD Decompression Speed vs Compression Level

[VipulGarg869]

I have been benchmarking the decompression speed of ZSTD at various compression levels. The documentation states that the decompression speed doesn't change much with the compression level. While that is roughly the case, I was still able to find that the decompression speed decreases up till compression level 6. Beyond level 6, it increases. What is the reason for this?