Question

あきまる

例えばHe saw a game the rules of which he was ignorant of.(先行詞はa gameでwhich=game)という文だったらhe was ignorant of the rules of a game.というやうに先行詞部分を代入できますよね。
写真の下線部のover whichの先行詞はthe length of timeです。先行詞部分を代入すると、people and place had had to wait the length of time over time(which=time)になるという認識でいいですか？