I'm trying to create a plot which has y axis exactly same with this :

And I'm in this situation and everything is ok until this point:

When i try this lines:

ax.set_yticks(range(20,67,10))
ax.set_yticklabels(['20','30','40','50','60'])

My graph is becoming this:

I couldn't understand how to set locations' of yticks properly.

Have you tried the following?

import numpy as np
ticks = np.linspace(20, 60, 5)
ax.set_yticks(ticks)
ax.set_yticklabels([str(int(x)) for x in ticks])