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

graphical.target @1min 30.045s
└─multi-user.target @1min 30.045s
  └─docker.service @53.816s +36.229s
    └─network-online.target @53.730s
      └─NetworkManager-wait-online.service @38.022s +15.707s
        └─NetworkManager.service @28.043s +9.975s
          └─dbus.service @28.041s
            └─basic.target @27.968s
              └─sockets.target @27.968s
                └─snapd.socket @27.966s +1ms
                  └─sysinit.target @27.836s
                    └─snapd.apparmor.service @27.196s +640ms
                      └─apparmor.service @24.944s +2.230s
                        └─local-fs.target @24.944s
                          └─mnt-daten.mount @24.403s +540ms
                            └─dev-sda4.device @24.377s