That article also only gives percentages for Japan and Spain, but lists the raw numbers in Table 1 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5990315/table/T... , so the missing percentages for China (10%), South Korea (10%) and United States (6%) can be calculated.
They don't measure fleet size by displacement but by number of vessels: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5990315/figure/... There doesn't appear to be a monotonic relationship between total subsidies and fleet size by that measure (e.g. Taiwan appears second by number of vessels after China but before Japan, despite their subsidies only amounting to 6% of the total).