This seems not an official chart from TechPowerUp. I searched for the reviews in TechPowerUp site and nothing is found. The only Kiwi Ears IEM I can find there is Orchestra. Nomally, if widely recognized, the image of curve should be easily found by Google (Image), e.g. seaching for "Kiwi Ears Melody" + "curve".
If I'm wrong, please copy paste a link of the TechPowerUp review. I'd like to see it too. Thanks.