Python 加点坐标有大神能不能帮一下

Question

import numpy as np

import pandas as pd

import matplotlib.pyplot as plt

%matplotlib inline

data = pd.read_csv("/resources/data/zr.csv") #导入文件

by_year = data.groupby(["Year description"]).size()

by_year.plot(kind = "line",alpha=1,figsize = [10,7],color = 'c',\

title = "The number of cancers that accompanied the increase in years increased",\

linewidth=3)

plt.ylabel("Disease discovery")

plt.grid(True)                     #加上校准线

plt.subplots_adjust(bottom=0.2)    #设置图像高度

plt.margins(0.1)                   #居中显示图像  

#for a, b in zip():

     #plt.text() 

     #有没有大神会在这两行加上每一年的点坐标