You want the nadirs to be between 90 and 149, you reduce if they go below 90. However, given that over 5 units you increased by 0.5 units at a time, it's OK to go down this time as you've just been doing 0.25 unit reductions.
You want the nadirs to be between 90 and 149, you reduce if they go below 90. However, given that over 5 units you increased by 0.5 units at a time, it's OK to go down this time as you've just been doing 0.25 unit reductions.