condition mean min max ZT0-3 1.838595 1.709425 1.967765 ZT4-7 4.990575 4.990575 4.990575 ZT8-11 5.136565 5.136565 5.136565 ZT12-15 0 0 0 ZT16-19 2.1225300000000002 2.1225300000000002 2.1225300000000002 ZT20-23 2.311 2.311 2.311