UnicodeDecodeError: ‘utf-8’ codec can’t decode byte 0x96 in position 35: invalid start byte

This happens because you chose the wrong encoding.

Since you are working on a Windows machine, just replacing

Past=pd.read_csv("C:/Users/.../Past.csv",encoding='utf-8') 

with

Past=pd.read_csv("C:/Users/.../Past.csv",encoding='cp1252')

should solve the problem.