Help, please with Chinese 4 Character blue underglaze inscription

[earlyblue]

Hello Experts and Novices!

Is there anyone out there who might be able to translate these 4 characters in underglaze blue?
I appreciate any input at all.

Thanks.

[peterp]

Zhongguo Fengxing

Zhongguo means "China". This alone already means it is 20th century. There was never a perception of "China" as a country name inside China before that.

The characters are simplified characters introduced by the PRC, as such it must be from about 1960 or later.