The data on the Pine Island Glacier comes from a Jan 2019 Paper -
https://www.pnas.org/content/116/4/1095Four decades of Antarctic Ice Sheet mass balance from 1979β2017They have extracted from a mass of previous studies, and they are confident enough on discharge data to produce analyses by years for data on nearly 200 sub-regions of Antarctica. But the SMB (mainly snowfall) data is not analysed by year, there are only 39 year totals.
But I am not a scientist worried about peer review. So on the attached graphs I have allocated SMB over years by the yearly average. I did this to show how a relatively small percentage annual increase in discharge leads to a high percentage increase in net mass loss.
In the 39 years of the analysis, discharge is estimated at nearly 4,000 GT, but with nearly 3,000 GT of SMB gain, net mass loss is just over 1,000GT. Half of that may well have happened in the first 30 years, half in the last 9 years.
The current annual net mass loss guesstimate is 65 GT a year. A pure guess at the future gives that increasing to over 100 GT per year in 10 years.