The .csv file that you import must look like the table on the right hand side:
The .csv file that you import must conform with these requirements:
The first row must be:
Load,SAST,SADT,TAST,TADT,TRDT,QADT
All the proportions (from all axle groups combined) must add up to 1.0 (or very close!)
Click here for more information on Importing your TLDs.