Write text outside plot but inside figure

I would like to add a text at the left of each line but I've not been able to do so.
I tried using

plt.annotate('Distance $\leq6.5$ $km$', (1, 1))
plt.text(1, 1, 'Distance $\leq6.5$ $km$')

but it always resulted into writing in the last subplot as shown on the screenshot.

Here is my current program:

import numpy as np
import numpy.random as rd
import matplotlib.pyplot as plt

Dic_Values = {'inf_6.5':{'v_moy':rd.randint(15,25, 20), 'cad':rd.randint(75,100,20), 'f_moy':rd.randint(130,180,20)},
              '6.5_9.5':{'v_moy':rd.randint(15,25, 11), 'cad':rd.randint(75,100,11), 'f_moy':rd.randint(130,180,11)},
              'sup_9.5':{'v_moy':rd.randint(15,25, 4), 'cad':rd.randint(75,100,4), 'f_moy':rd.randint(130,180,4)}}


def bilan_course():
    types = list(Dic_Values.keys())
    c = 0
    plt.figure(figsize=(21,7))
    Labels = ['S_moy', 'Cad', 'F_moy']
    Y_axis = ['S (in $km \cdot h^{-1}$)', 'Cad (in $step\cdot min^{-1}$)', 'F (in $beat\cdot min^{-1}$)']
    for ty in types:
        Donnees = Dic_Values[ty]
        Cles = list(Donnees.keys())
        for v in range(len(Cles)):
            plt.subplot(int('33'+str(3*c+v+1)))
            plt.plot(Donnees[Cles[v]], label=Labels[v])
            plt.xlabel('Course')
            plt.ylabel(Y_axis[v])
            plt.title(Labels[v])
            plt.ylim(0, max(Donnees[Cles[v]])*1.1)
            plt.legend(loc='best')
        c+=1

    plt.subplots_adjust(left=0.1, bottom=0.085, right=0.95, top=0.882, wspace=0.25, hspace=0.5)
    plt.annotate('Distance $\leq6.5$ $km$', (1, 1), fontsize=12)
    plt.suptitle('Summary', fontweight='bold')
    plt.show()

I guess it's time to make yourself familiar with the "expicit" API of matplotlib
(see matpltolib docs on APIs)

In short, if you use plt.< do something > matpltolib will always try to identify the most recently used axes and use it!
To address an explicit axes, call the method on the axes object you actually want to use!

Here's a quick snippet that should help you to get started:

import matplotlib.pyplot as plt

f, axes = plt.subplots(3, 3, figsize=(10, 6))

for i, ax in enumerate(axes.flat):
    ax.plot([1,2,3])
    ax.set_title(f"this is ax {i}")
    ax.set_xlabel(f"x-label for ax {i}")
    ax.set_ylabel(f"y-label for ax {i}")
    
    ax.text(.25, .1, f"text on ax {i}", ha="left", va="bottom",
            transform=ax.transAxes, color="r")
    
f.tight_layout()