The newest numbers were edited upward from the old ones, based on this empirical test that @mutantbass found
and beyond that, they are all ratios based on conductor cross-section, so for example a 0.15mm x 12mm strip would have 150% the cross-sectional area of a 0.15mm x 8mm strip. (1.8mm² vs 1.2mm²)
The more information, the better. Testing with dummy cells wired inside a fake pack would be even better.