1"Since" — indicating that something has continued from a particular event or point in time up to the present.
引っ越して以来、一度も故郷に帰っていない。
I haven't gone back to my hometown once since I moved.
あの映画を見て以来、彼女は俳優を目指すようになった。
Since watching that movie, she has aspired to become an actress.
先月の値上げ以来、客足が減っている。
Since last month's price increase, customer numbers have been decreasing.
入社以来、彼はずっと同じ部署で働いている。
He has been working in the same department ever since joining the company.