有错误.第一个逗号可以去掉,然后最后那个 in a 200% 是错误的,直接改为 by 200%.
正确句子：I have to tell you that recently the fan kidnap cases have increase by 200%.
这样才是正确的句子.
自己认真回答的,
希望及时采纳—— ♥ 多谢 ⌒_⌒