condition mean min max ZT0-3 53.08538 53.08538 53.08538 ZT4-7 49.6355595 49.6355595 49.6355595 ZT8-11 60.087263500000006 60.087263500000006 60.087263500000006 ZT12-15 31.646871500000003 31.646871500000003 31.646871500000003 ZT16-19 65.98462549999999 65.98462549999999 65.98462549999999 ZT20-23 64.104338 64.104338 64.104338