condition mean min max ZT0-3 11.28050372 7.09205104 15.4689564 ZT4-7 25.6161219275 18.41184508 32.820398775 ZT8-11 40.89222606 35.565451185 46.219000935 ZT12-15 57.562186337499995 57.200798545 57.92357412999999 ZT16-19 63.61460856749999 60.384246995 66.84497013999999 ZT20-23 65.28303044750001 61.710801665000005 68.85525923