readPercentage( data ) {

			const chunk = this.readChunk( data );
			let value;

			switch ( chunk.id ) {

				case INT_PERCENTAGE:
					value = this.readShort( data ) / 100;
					break;

				case FLOAT_PERCENTAGE:
					value = this.readFloat( data );
					break;

				default:
					this.debugMessage( '      Unknown percentage chunk: ' + chunk.toString( 16 ) );

			}

			this.endChunk( chunk );
			return value;

		}
Read percentage value.

@method readPercentage
@param {DataView} data Dataview to read data from.
@return {Number} Data read from the dataview.