npArray = [60, 70, 70, 70, 80, 90, 60]
counter = {}
for item in npArray:
if item in counter:
counter[item] += 1
else:
counter[item] = 1
arraySize = len(npArray)
nbOfOccurrences = counter.get(60, 0)
proba = (nbOfOccurrences / arraySize) * 100
print(proba)
