condition mean min max ZT0-3 179.826705 179.826705 179.826705 ZT4-7 160.1342545 160.1342545 160.1342545 ZT8-11 216.85925 216.85925 216.85925 ZT12-15 221.395351 221.395351 221.395351 ZT16-19 230.86808000000002 230.86808000000002 230.86808000000002 ZT20-23 217.149096 217.149096 217.149096