https://bbs.wenxuecity.com/currentevent/3670312.html
20%， announced before 4/2
34%， announced 4/2, 累计 54%
50%, announced 4/7, 累计104%
announced 125% 4/9 ： https://www.bbc.com/news/articles/c5y66qe404po
announced 145% 4/10， it is 125%+20% （before 4/2）。
announced exempt for smartphones, computers, some electronics, 4/12. This accounts about more than 1/4 of all china imports.
20+10=30%， announced 5/12 (after negotiation). https://www.bbc.com/news/articles/czx0ry7kdk5o
