3D plots - Proper x & y axis scaling

Hello,

I've been trying to find a way to plot the data I have with the proper scaling of the x & y axis. The information I have is from test data, where I have calculated the gibbs energy of the test conditions. I have a set of data of particle measurements that are given in size ranges, but I'm not able to get the data properly graphed with the scaling I'm needing.

The information is in the attached file.