condition mean min max ZT0-3 9.643073 9.643073 9.643073 ZT4-7 9.0202705 9.0202705 9.0202705 ZT8-11 9.267600999999999 9.267600999999999 9.267600999999999 ZT12-15 7.661111 7.661111 7.661111 ZT16-19 9.123267 9.123267 9.123267 ZT20-23 8.609028 8.609028 8.609028