condition mean min max ZT0-3 3.3533049999999998 2.09944 4.147685 ZT4-7 1.4845000000000002 1.4845000000000002 1.4845000000000002 ZT8-11 2.37593 2.37593 2.37593 ZT12-15 3.677935 3.65205 3.7038200000000003 ZT16-19 4.459465 4.459465 4.459465 ZT20-23 4.845409999999999 4.845409999999999 4.845409999999999