Given an array of strings, write a program in Python to calculate the number of occurrences for each string.
['Hello', 'World', 'Hello', 'World', 'Foo', 'Bar']
words = ['Hello', 'World', 'Hello', 'World', 'Foo', 'Bar']

from collections import Counter
word_count = Counter(words)

for word, count in word_count.items():
 print(f'{word} : {count}')