The time after the unit is active or started is printed after the "@" character.
The time the unit takes to start is printed after the "+" character.

graphical.target @30.394s
└─gdm.service @29.795s +598ms
  └─systemd-user-sessions.service @26.524s +361ms
    └─network.target @26.521s
      └─networking.service @20.093s +6.427s
        └─apparmor.service @15.701s +3.970s
          └─local-fs.target @15.699s
            └─boot-efi.mount @15.389s +310ms
              └─systemd-fsck@dev-disk-byx2duuid-1860x2d9879.service @14.786s +574ms
                └─dev-disk-byx2duuid-1860x2d9879.device @14.785s