残業代　割増率
http://www.zangyou7.com/kiso_chinggin/post_2.html
http://www.roudousha.net/zangyo/001calc_way.html
https://www.kisoku.jp/z/ritu.html
http://www.mhlw.go.jp/general/seido/chihou/kaiketu/soudan.html
http://www.mhlw.go.jp/stf/seisakunitsuite/bunya/koyou_roudou/roudoukijun/mail_madoguchi.html
https://www.jtuc-rengo.or.jp/activity/roudou/roudoujikan/
http://labor.tank.jp/jikan/zangyo_keisan.html
https://jsite.mhlw.go.jp/tokyo-roudoukyoku/var/rev0/0139/1618/2013327144331.pdf
https://www.jtuc-rengo.or.jp/shuppan/roudou/roudou/data/2017_36kyoteihandbook/html5.html#page=9
https://www.jtuc-rengo.or.jp/activity/roudou/data/fubarai_bokumetsu.pdf