us >> use
sy : ??
ni : ??
id >> idle
wa >> wait
hi >> ??
si >> ??
st >> ??
What is the max value we can tolerate for the wait (wa) parameter?
us: % CPU utilised for user processes
sy: % CPU utilised for system processes
ni: % CPU utilised for "niced" processes
id: % CPU idle / unutilised
wa: indicates processes waiting on disk IO (IO Wait)
hi: hardware interrupts
si: software interrupts
From what you've pasted you can infer that your CPU(s) a 65.3% idle with 10.2% being used for user processes, 1.9% on system processes and 22.6% waiting on IO.
22.6% isn't too bad for IO wait. IO wait will go up if you are swapping a lot (not enough RAM) and can sometimes indicate a failing disk. A better tool for analysing IO problems is iostat.