The end of life refrigerant loss (MR) has a range of 2%-10%. The reference guide says I can use a lower than the 10% default rate if I can demonstrate how the lower rate is justified. How would I go about trying to justify the use of a lower end of life leakage rate instead of the 10% default when the equipment is only half way through its anticipated life?

Currently actual leakage rate over 12 years is 0.38%