7Zip 9.04 compression times

Using a 547Mb MySQL backup file I observed the following compression times for the respective compression settings.

1 > 30.18 Mb in 22s
2 > 30.18 Mb in 23s
3 > 29.12 Mb in 26s
4 > 29.12 Mb in 26s
5 > 22.03 Mb in 4m10s
6 > 22.03 Mb
7 > 19.51 Mb in 6m3s
8 > 19.51 Mb
9 > 17.31 Mb in 6m10s