ArmorDropChances and HandDropChances not working

The game won't pay attention to either the ArmorDropChances or the HandDropChances. I used the command:

/summon Skeleton ~ ~1 ~ {SkeletonType:1,ArmorItems:[{},{},{},{id:skull,Damage:3s,tag:{SkullOwner:kingplayer855}}],HandItems:[{id:blaze_rod,tag:{display:

{Name:Fire Staff}

,ench:[

{id:20,lvl:10}

]}},{}],HandDropChances:[0:1.0f,1:1.0f]}