any determinations regarding the award of, and the amount of, employer-provided grants or rights that are based on performance are—
(i)#
made based upon meeting previously established performance criteria (which may include hours of work, efficiency, or productivity) of any business unit consisting of at least 10 employees or of a facility, except that, any determinations may be based on length of service or minimum schedule of hours or days of work; or
(ii)#
made based upon the past performance (which may include any criteria) of one or more employees in a given period so long as the determination is in the sole discretion of the employer and not pursuant to any prior contract.