Plotting Y-Axis on X-Axis as percentage?

Hi I am trying to read data the y-axis data from a txt file and separate the points in percentages as 5% percent each...5, 10, 15... for each separation [y-axis] and check the distance between each point.

However I am unable to do so as I get that the X and Y axis are different lengths

For the X-axis I try to use percentFormatter(xmax=20) but it gives me 1 as length

For the Y-axis I read data from a text file and set it as numpy array, sort it by ascending and it gives 200 length

Would be great to know also how to do so using a scatter graph

import matplotlib.pyplot as plt
import matplotlib.ticker as ticker
import numpy as np

data = np.loadtxt("nb_with.txt", delimiter="\n", unpack=True)
y = np.array(data)
y.sort()
plt.plot(y, 'r+')
plt.show()