smartctl --scan | awk '{print $1}' | xargs -I {} sh -c 'echo -n "{}: "; smartctl -A {} | awk "/Power_On_Hours/ {printf \"%.2f years\n\", \$10/8760}"'

/dev/sda: 0.30 years #14TB WD Elements (shucked)
/dev/sdb: 2.64 years #8TB WD My Book (shucked)
/dev/sdc: 12.37 years #3TB WD Red
/dev/sdd: 2.86 years #12TB My Book (shucked)
/dev/sde: 13.47 years #3TB WD Red
/dev/sdf: 1.26 years #14TB WD Elements (shucked)
/dev/sdg: 10.55 years #5TB WD Red

Most of these drives served on Windows Server bare metal w/ StableBit DrivePool + SnapRAID before migrating to Proxmox mergerfs + SnapRAID & ZFS. My raidz1 pool has a combine total of 36+ years lol. Yes I do have backups. :)