The example multiplies
y by
exp(−1) for each two-unit step, so its ratio stays constant while the ordinary amount lost changes. The values approximately 1000, 367.879, 135.335, and 49.787 do not have equal numerical differences. Their decimal-log positions do have equal differences. Keep ratios, ordinary differences, and transformed slope separately labeled so a regular-looking line does not imply constant subtraction from the untransformed values.