$ du /usr/share/man/man?
15348   /usr/share/man/man1
1960    /usr/share/man/man2
49844   /usr/share/man/man3
308     /usr/share/man/man4
2776    /usr/share/man/man5
12      /usr/share/man/man6
1180    /usr/share/man/man7
4636    /usr/share/man/man8
4       /usr/share/man/man9
4       /usr/share/man/mann

$ du -h /usr/share/man/man?
15M     /usr/share/man/man1
2.0M    /usr/share/man/man2
49M     /usr/share/man/man3
308K    /usr/share/man/man4
2.8M    /usr/share/man/man5
12K     /usr/share/man/man6
1.2M    /usr/share/man/man7
4.6M    /usr/share/man/man8
4.0K    /usr/share/man/man9
4.0K    /usr/share/man/mann
