Why does the output of the top command show more than 100% CPU utilization for a process?

Issue

• The output of top command shows that "XXXX" process is using more than 100% CPU utilization.

top - 09:11:37 up  2:37,  1 user,  load average: 0.89, 3.56, 3.72
Tasks: 398 total,   1 running, 397 sleeping,   0 stopped,   0 zombie
Cpu(s):  6.1%us,  2.3%sy,  0.0%ni, 88.5%id,  3.0%wa,  0.0%hi,  0.1%si,  0.0%st
Mem:  24605544k total,  3007220k used, 21598324k free,    63632k buffers
Swap: 18579448k total,     5748k used, 18573700k free,   732280k cached

PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND            
9029 mysql     20   0 4856m 1.1g 4092 S 111.5  4.9  66:25.56 XXXX            
22173 apache    20   0  626m  22m 9856 S 23.2  0.1   0:04.35 httpd              
21935 apache    20   0  625m  25m  12m S  5.8  0.1   0:03.12 httpd