[USER (data scientist)]: Cool, now I want to make a matrix with suburbs as rows, years as columns, and the number of properties sold as values. Please generate a DataFrame to summarize the yearly demand for affordable properties by suburb in the Melbourne housing market, and save this summary as a pickle file.
My template of code snippet is:

---BEGIN CODE TEMPLATE---

import pandas as pd
import pickle

melbourne_housing = pd.read_csv("melb_data.csv") 

# YOUR SOLUTION BEGIN:
<code1>
[GENERATE YOUR CODE]
</code1>
# YOUR SOLUTION END:

print(suburb_yearly_demand_pivot)

# save data
pickle.dump(suburb_yearly_demand_pivot,open("./pred_result/suburb_yearly_demand_pivot.pkl","wb"))

---END CODE TEMPLATE---

[YOU (AI assistant)]: Sure thing! You can use the pivot_table function from pandas like this: 
