condition mean min max ZT0-3 18.28985 18.28985 18.28985 ZT4-7 14.4207 14.4207 14.4207 ZT8-11 14.0586 14.0586 14.0586 ZT12-15 16.061500000000002 16.061500000000002 16.061500000000002 ZT16-19 19.1066 19.1066 19.1066 ZT20-23 21.134050000000002 21.134050000000002 21.134050000000002