1990 | 2000 | 2010 | 2020 | |
Vol. Difference (After less Before)-mm | −750 | −710 | −790 | −720 |
Sum of fluxes (mm) | −737 | −687 | −788 | −710 |
Error (mm) | −13 | −23 | −2 | −10 |
Error (%) | 1.8 | 3.2 | 0.3 | 1.4 |
Accuracy (%) | 98.2 | 96.8 | 99.7 | 98.6 |