如何在seaborn FacetGrid中的条形顶部添加百分比？

import seaborn as sns
import matplotlib.pyplot as plt

grid = sns.FacetGrid(data, col='column_name', size=4, aspect=1.5)

grid.map(sns.barplot, 'x', 'y')
for ax in grid.axes.flat:
    # 计算每个类别的百分比
    total = len(data[data['column_name'] == ax.get_title()])
    for p in ax.patches:
        height = p.get_height()
        ax.text(p.get_x() + p.get_width() / 2, height + 5, f'{height/total:.1%}', ha="center")

plt.show()