The present disclosure relates to a method and apparatus for measuring performance of a storage system. An access relaying apparatus has a plurality of proxy servers 23, an administration server 24 for statistic processing, and a shared disk 25 accessible from them. One embodiment includes 16 sensor groups in which each sensor group has a dedicated return line. The ramp pivots on the new tailgate structure as the load moves upwards on the ramp and eliminates the change in angle as it occurs at the juncture of the inclined portion of the ramp and the truck bed. The compositions are useful in organic electronic devices.