ราคาบ้านตกต่ำและการจำนองที่ติดลบ

import numpy as np
import pandas as pd

# Cumulative drop in home value over time as a ratio
cumulative_decline_forecast = np.cumprod(1+decline_array)

# Forecast the home value over time
home_value_forecast = ____

# Find all periods where your mortgage is underwater
underwater = ____
pd.value_counts(underwater)

# Plot the home value vs principal remaining
plt.plot(home_value_forecast, color='red')
plt.plot(principal_remaining, color='blue')
plt.legend(handles=[homevalue_plot, principal_plot], loc=2)
plt.show()