论文要用到RTA历年数据，在 WTO里面下载后整理数据协议生效发现有两个指标，（G）和（S）请问有什么区别呢，该用哪一个？链接：WTO | Regional trade agreements

Date of entry into force (G):	17-May-2010	End of implementation period:	2025
Date of entry into force (S):	12-Aug-1998