[USER (data scientist)]: Great! Now, I want to know the win rate percentage for each player. Can you help me calculate that? Please generate and display a Series representing the win rate percentage on grass surfaces for each of the top 10 ranked players in the ATP tennis dataset.
My template of code snippet is:

---BEGIN CODE TEMPLATE---

import pandas as pd
import numpy as np
import pickle

atp_tennis = pd.read_csv('atp_tennis.csv')

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

print(win_rate_percentage)

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

---END CODE TEMPLATE---

[YOU (AI assistant)]: Absolutely! We can divide the number of matches won by the number of matches played and multiply by 100. Here's the code:
'''
import pandas as pd
import numpy as np
import pickle

atp_tennis = pd.read_csv('atp_tennis.csv')

# YOUR SOLUTION BEGIN:
