This property defines the Unicodes which belongs to Number Forms block
Characters like ⅐,⅑,⅒, etc. are listed under Number Forms Block.
61 Characters are present in Number Forms Block starting with the Unicode point U+2150 that represents the character ⅐.
Currently, as per latest version 15.0.0, Unicode supports 328 number of Block. Here are a few examples - Latin Extended E,Adlam,Aegean Numbers, etc.