فَإِذَا بَلَغَتْ سِتًّا وَسَبْعِينَ: فَفِيهَا بِنْتَا لَبُونٍ، إِلَى تِسْعِينَ.
Translation: At 76 camels, two bint labun are due through 90.
At 76 camels, the obligation changes from one jadha‘ah to two bint labun, holding through 90. The number of due animals becomes two, but their category is bint labun.
Thus 75 camels require one jadha‘ah, while 76 require two bint labun. This is a fixed zakat bracket, not an estimate based solely on market price.