 <translate> Give the step-by-step reasoning process and then the final answer. Next year, there will be twice as many people going to the fair as are going this year, and the number of people who went to the fair last year was 200 less than those going next year. If the number of people going to the fair this year is 600, calculate the number of people at the fair in the three years. <yor> Ṣàlàyé bí wọ́n ṣe ń ronú lẹ́ẹ̀kan-lẹ́ẹ̀kan, kó o sì wá sọ ìdáhùn tó o máa fún wọn. Ọdún tó ń bọ̀, iye àwọn tó máa lọ síbi àpérò náà yóò fi ìlọ́po méjì ju iye àwọn tó ń lọ lọ́dún yìí lọ, iye àwọn tó sì lọ síbi àpérò náà lọ́dún tó kọjá kéré ní igba èèyàn sí iye àwọn tó ń lọ lọ́dún tó ń bọ̀. Bí iye àwọn ènìyàn tó ń lọ sí ibi àríyá lọ́dún yìí bá jẹ́ 600, ṣe ìṣirò iye àwọn ènìyàn tó wà ní ibi àríyá ní ọdún mẹ́ta. 