arrs = [arr1, arr2, arr3]
idx = [(np.ones(len(a)) * i) for i, a in enumerate(arrs)]
(rows, cols), table = npi.count_table(np.concatenate(idx), np.concatenate(arrs)
    )
table = table / table.sum(axis=1, keepdims=True)
print(table * 100)
Calculate percentage of count for a list of arrays