Im trying to get the number max of a category of a csv file, but i cant get why my fonction is not working

import csv

file = open("serieschrono-datagouv.csv", "r", encoding="utf8")
reader = csv.reader(file, delimiter=";")
table =[]
for row in reader:
    ligne = []
    for i in row:
        ligne.append(i)
    table.append(ligne)
file.close()

def maximum(liste, donnée):
    maxi = liste[1][0]
    for i in range(1,len(liste)):
        if liste[i][2]==str(donnée):
            if liste[i][0] !='NA':
                if maxi < liste[i][0]:
                    maxi = liste[i][0]
    return maxi

BTW the image is the csv file

I tryed to change a lot of things in the fonction