condition mean min max ZT0-3 15.447419 15.447419 15.447419 ZT4-7 16.895343 16.895343 16.895343 ZT8-11 18.559475499999998 18.559475499999998 18.559475499999998 ZT12-15 15.7759205 15.7759205 15.7759205 ZT16-19 16.5327355 16.5327355 16.5327355 ZT20-23 16.756788 16.756788 16.756788