Percentages are more useful than numbers for making decisions about time and money.
If you make $10,000 or $1,000,000 and spend 100% of it, the outcome is the same.
No time in the bank.
Money is a store of optionality, which makes it a tool for "making" time.
Life is an incredibly different experience for someone who has 12 months of expenses in the bank vs. 2 weeks.
There are only two ways to change the percentage: make more or spend less.