spawns.txt

<event>
  <outcome affected_mobs="zombie">
    <action_group>
      <actions>
        <set_hp>
          <value ratio="1">40</value>
          <value ratio="1">50</value>
          <value ratio="1">60</value>
        </set_hp>
      </actions>
    </action_group>
  </outcome>
</event>

#########Anything below this are comments I'm making from pastebin, they aren't included in the spawns.txt
The expected output was that zombies would have 20~30 hearts of health, chosen randomly. However, they still seem to have 10 hearts.