top命令的TIME/TIME+是指的進程所使用的CPU時間，不是進程啟動到現在的時間，因此，如果一個進程使用的cpu很少，那即使這個進程已經存在N長時間，TIME/TIME+也是很小的數值。
此外，如果你的系統有多個CPU，或者是多核CPU的話，那麼，進程占用多個cpu的時間是累加的。
原版英文說明如下：
l: TIME — CPU Time
Total CPU time the task has used since it started. When ‘Cumulative mode’ is On, each process is listed with the cpu time that it and its dead children has used. You toggle ‘Cumulative mode’ with ‘S’, which is a command-line option and an interactive command. See the ‘S’ interactive command for additional information regarding this mode.
m: TIME+ — CPU Time, hundredths
The same as ‘TIME’, but reflecting more granularity through hundredths of a second.