Cumulative water mass-loss rate of comet 67P from July 2014 to September 2016. About 40% more mass is lost post-perihelion than pre-perihelion (~1.4 vs. 1 million tons), but mid-point (50% cumulative loss) is close to the solstice (vertical red dotted line). Ninety-eight percent of the mass is cumulatively lost within ±200 days from perihelion, and 95% between the two equinoxes (vertical blue dotted lines). The total water loss is 2.42 ± 0.04 × 10⁹ kg.