Max() from a CSV column: ValueError: max() arg is an empty sequence

Question

I am trying to open a csv and then us the columns to find totals and averages but I keep getting a value error when attempting to return the max height

with open('athlete_events_short.csv', 'r', newline='') as athletes:
    reader = csv.reader(athletes)
    header = next(reader)
    
    
    for line in reader:
        new_athlete = Athlete(line[1], line[2], line[3], line[4], line[5], line[6], 
            line[7], line[8], line[9], line[10], line[11], line[12], line[13], line[14])
        athlete_list.append(new_athlete)
        
    
        
    for athlete in athlete_list:
        age_total += athlete.get_age()
        weight_total += athlete.get_weight()
        height_total += athlete.get_height()
        max_height = max(reader, key=lambda column: (column[5].replace(',',''))) # this works but it returns a letter..not the max number

print(f'Average age in years for all olympians = {age_total/len(athlete_list):.2f}')
print(f'Average weight for all olympians = {weight_total/len(athlete_list):.2f} kilograms')
print(f'Average height for all olympians = {height_total/len(athlete_list):.2f} centimeters')
print(f'The tallest of all olympians is = {max_height:.2f} centimeters') # I can not get this to work.