Number average for nobody

I cant execute the break when i put in 999 it just keeps asking for more scores somone help

score = 0

total_score = 0

while True:
    scores = float(input("Enter test score: ")
    if score in range (0,100):
        total_score = score + total_score
        score = score + 1
     
    elif score = 999:
         break
    else:
        print("Test score must be from 0 through 100")

average_score = total_score / score
print("Total score", total_score )
print("Average Score", average_score)