Without further context, 'for' seems wrong in all of your sentences and should be omitted. These are OK: 1. The highest percentage was China with 70% in 1990.
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RavinathHow can a percentage(a numerical value) be a COUNTRY? Shouldn't be there a supportive word like a preposition every time?It depends on what is being evaluated. As I stated, you have supplied no context that suggests your preposition is appropriate.