Define axis characteristics. AXIS1 suppresses the horizontal axis label and uses the OFFSET= option to move the first and last major tick mark values away from the vertical axes so bubbles are not clipped. AXIS2 uses the ORDER= option to set major tick mark intervals. This could be done with the VAXIS= option on the BUBBLE statement, but then you could not suppress the axis label and alter other axis characteristics.

axis1 label=none
      offset=(5,5);
axis2 order=(0 to 40000 by 10000)
      label=none;