Yes, that's what I wrote: ten processes all repeating this pattern : fighting to get the CPU during 1 second then idling for 9 seconds.
The load average is not really an average, there are three load average values maintained by the kernel, the 1min, the 5min and the 15min one. They are updated at worst every second. The load is 10 during one second and zero for the remaining 9 seconds. The kernel function that computes the load average is smoothing this to a load of 1.
One unit of load in average for every second of the minute, including the first one.
The load average is updated every second from the run queue statistics which are sampled every 10 ms. (Note that I might be wrong here, it is well possible that starting from Solaris 10, the run queue is also computed from micro-state accounting instead of being sampled. That doesn't affect what we are talking about here).
There are six periods of 10 seconds in one minute, not five, hence 6/60*100=10%