Load average out of proportion to vmstat?

My load averages seem to be much higher than vmstat would indicate. I have ~100% idle, but load averages of 0.54. To me, 0.54 load average would be approximately (with 4 CPU cores, as my linode has) about 14% user+system+iowait.

Am I missing something here?

# uptime ; vmstat 5 5 ; uptime
 20:30:19 up 6 days, 12:46,  3 users,  load average: 0.54, 0.69, 0.54
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa
 0  0  68440  36920  39084 289696    0    0     6     6    5    7  0  1 98  0
 0  0  68440  36868  39084 289696    0    0     0     0  240  102  0  0 100  0
 0  0  68440  37092  39084 289696    0    0     0     0  299  121  0  1 99  0
 0  0  68440  36828  39088 289696    0    0     0   267  244   96  0  0 99  0
 0  0  68440  34928  39088 289716    0    0     0   571  431  137  0  0 99  0
 20:30:39 up 6 days, 12:46,  3 users,  load average: 0.67, 0.71, 0.55