Both donation percentage and fleet member donation status are calculated at the same time. Donation contribution percentages are not individually calculated on their own, but rather donation percentages for each resource will differ. Energy > Planet Resources = Food > Coins

For example: (suppose the donation ratio of coins to food is 1:2)
Stage 1 >> 150,000 Coins
The donation percentage is calculated as follows
Member 1: Contributes 100,000 coins, 67%
Member 2: Contributes 50,000 coins, 33%
Member 3: Doesn't donate, 0%
Member 4: Doesn't donate, 0%

Stage 2 >> 15,000 Food Items
Total donation percentages are calculated as follows (including percentages from Stage 1)
Member 1: Contributes 7,500 food items, 64%
Member 2: Doesn't donate, 28%
Member 3: Contributes 5,500 food items, 6%
Member 4: Contributes 2,000 food items, 2%