Zhengzhou Open
Singles

Year
Champion
Runner-up
Score
↑ WTA Premier event ↑
↑ WTA Premier event ↑
↑ WTA Premier event ↑
↑ WTA Premier event ↑
2018
China Zheng Saisai
China Wang Yafan
5–7, 6–2, 6–1
2017
China Wang Qiang
China Peng Shuai
3–6, 7–6(7–3), 1–1 ret.
↑ WTA 125K event ↑
↑ WTA 125K event ↑
↑ WTA 125K event ↑
↑ WTA 125K event ↑
2016
Russia Anastasia Pivovarova
China Lu Jingjing
6–4, 6–4
2015
China Wang Yafan
China Duan Yingying
6–4, 6–4
2014
China Zhang Kailin
China Xu Yifan
7–5, 6–4
↑ ITF event ↑
↑ ITF event ↑
↑ ITF event ↑
↑ ITF event ↑

Question: What year did the Zhengzhou Open was first held as an ITF tournamenrvand when did it transition to a WTA type tournament?
Answer: The Zhengzhou Open has been held since 2014, as an ITF tournament and then as WTA 125K tournament in 2017 and 2018.