amazing sed

I have a file:
  7 P-states (frequencies)
  8   2.81 Ghz   100.0%
  9   1400 Mhz     0.0%
 10   1050 Mhz     0.0%
 11    700 Mhz     0.0%
 12    350 Mhz     0.0%
I could grep out the P-states line,but what i want is the next line,to extract  the 100,and How?
It's sed,and thanks to kexin.the code is:

  3 val=`sed -n -e  '/P-states/{
  4 n
  5 p
  6 }' busy.output | awk '{print $3}'`
  7
  8 echo $val
  9
 10 val=${val%.*}
 11
 12 echo $val

and "n" means i put the next line to pattern space,and "p" prints it,great!