The IBM Large System Performance Reference (LSPR) ratios represent IBM's assessment of relative processor capacity in an unconstrained environment for the specific benchmark workloads and system control programs specified in the tables. 

For more details please see this web page. 

The tables show the MSUs (million service units) and PCIs (Processor Capacity Index) for the IBM Z processor capacity settings based on z/OS 2.2 workloads.

The MSUs describe the processor usage measured for a workload and are the base for e.g. sub-capacity pricing. 

The table with the MSU / PCI values is here.