Selection sort vs Bubble sort algorithm

Question

I am learning the time complexity of bubble sort and selection sort using Python. In theory selection sort is said to be faster than bubble sort ,however my programs written in Python indicates both of them take almost the same time for execution.

My graphs:

my code:

import numpy
import time
import matplotlib.pyplot as plt

n = 1000
selection = {}
bubble = {}
while n<=10000:
    a = numpy.random.randint(low=1 , high= 100 , size= n)

    #selection sort
    start = time.time()
    for i in range(n-1):
        idx = i
        for j in range(i+1 , n):
            if a[j] < a[idx]:
                idx = j
        a[i] , a[idx] = a[idx] , a[i]
    end = time.time()
    selection[n] = end-start

    #bubble sort
    start = time.time()
    for i in range(n-1):
        for j in range(n-1-i):
            if a[j] > a[j+1]:
                a[j] , a[j+1] = a[j+1] , a[j]
    end = time.time()
    bubble[n] = end-start

    n+=1000

print(selection , bubble)            
plt.plot(selection.keys() , selection.values() , label="selectionSort")
plt.plot(bubble.keys() , bubble.values() , label="bubbleSort")
plt.xlabel("n")
plt.ylabel("time")
plt.show()

Can anyone help me understand this abomination?

Edit: problem was I was giving sorted array to bubble sort

New graph for the record: