condition mean min max ZT0-3 250.078211 250.078211 250.078211 ZT4-7 598.9985495 598.9985495 598.9985495 ZT8-11 562.939357 562.939357 562.939357 ZT12-15 359.4499975 359.4499975 359.4499975 ZT16-19 246.2526375 246.2526375 246.2526375 ZT20-23 214.92098 214.92098 214.92098