condition mean min max ZT0-3 446.936402 446.936402 446.936402 ZT4-7 204.092847 204.092847 204.092847 ZT8-11 160.54289699999998 160.54289699999998 160.54289699999998 ZT12-15 207.9626625 207.9626625 207.9626625 ZT16-19 150.390279 150.390279 150.390279 ZT20-23 73.6153745 73.6153745 73.6153745