If you should be worried or not depends on what the data represents. If it's per cpu then you have a "100%" for every cpu. Say, if the server it's a quad processor you could have a total load of 400%.
That said, it's possible to have an overload or spikes because the processes are putted on queue. Here you ave a simple but good reading
http://blog.scoutapp.com/articles/2009/07/31/understanding-load-averages
A single-core CPU is like a single lane of traffic. Imagine you are a
bridge operator ... sometimes your bridge is so busy there are cars
lined up to cross. You want to let folks know how traffic is moving on
your bridge. A decent metric would be how many cars are waiting at a
particular time. If no cars are waiting, incoming drivers know they
can drive across right away. If cars are backed up, drivers know
they're in for delays.
Before upgrading i would check top and optimize apache and php processes.