condition mean min max ZT0-3 11.591368 11.591368 11.591368 ZT4-7 14.4169745 14.4169745 14.4169745 ZT8-11 18.1332865 18.1332865 18.1332865 ZT12-15 20.1186655 20.1186655 20.1186655 ZT16-19 17.6179565 17.6179565 17.6179565 ZT20-23 15.0592635 15.0592635 15.0592635