Pandas中如何高效查找比当前行值大的数据个数？

    col1  col2  col3
0    5.5   2.5  10.0
1    2.0   4.5   1.0
2    2.5   5.2   8.0
3    4.5   5.8   4.8
4    4.6   6.3   9.6
5    4.1   6.4   9.0
6    5.1   2.3   3.0
7    5.1   2.3  11.1
8    5.1   2.3  10.0
9    5.1   2.3  11.1
10   5.1   2.3  20.0
11   5.1   2.3  31.0
12   5.1   2.3   5.0

import numpy as np
import pandas as pd

data = [[5.5, 2.5, 10.0], [2.0, 4.5, 1.0], [2.5, 5.2, 8.0],[4.5, 5.8, 4.8], [4.6, 6.3, 9.6],[4.1, 6.4, 9.0],[5.1, 2.3, 3],[5.1, 2.3, 11.1],[5.1, 2.3, 10],[5.1, 2.3, 11.1],[5.1, 2.3, 20],[5.1, 2.3, 31],[5.1, 2.3, 5]]
df = pd.DataFrame(data, columns=['col1', 'col2', 'col3'])

df['col4'] = [np.sum(df['col3'][:i+1].values > val) for i, val in enumerate(df['col3'])]

print(df)

    col1  col2  col3  col4
0    5.5   2.5  10.0     0
1    2.0   4.5   1.0     0
2    2.5   5.2   8.0     1
3    4.5   5.8   4.8     0
4    4.6   6.3   9.6     3
5    4.1   6.4   9.0     0
6    5.1   2.3   3.0     0
7    5.1   2.3  11.1     7
8    5.1   2.3  10.0     0
9    5.1   2.3  11.1     1
10   5.1   2.3  20.0    10
11   5.1   2.3  31.0    11
12   5.1   2.3   5.0     0