condition mean min max ZT0-3 40.370336 40.370336 40.370336 ZT4-7 39.731727 39.731727 39.731727 ZT8-11 41.1308925 41.1308925 41.1308925 ZT12-15 51.6854705 51.6854705 51.6854705 ZT16-19 59.036430499999994 59.036430499999994 59.036430499999994 ZT20-23 56.7115515 56.7115515 56.7115515