What are the spirit-generating mechanics for Crippling Wave - Rising Tide?

In the skill description for Crippling Wave - Rising Tide, it is stated that

Critical Hits generate an additional 5 Spirit.

Since Crippling Wave typically hits multiple enemies with each use, is the 5 additional spirit generated for a critical hit per enemy, or per use of Crippling Wave?

(the same question applies for Fists of Thunder - Quickening and Deadly Reach - Strike from Beyond, but I'm mainly interested in the rune with Crippling Wave, since it tends to hit many more enemies)

I did a test in 1.03 and the Spirit generation is per crit hit per enemy, so if one Crippling Wave hit 5 enemies out of which 2 were crit hits, 10 additional Spirit was generated.