-- and this is true. But take the paralyzed man being lowered through the roof by his four friends. How many were in line to see Jesus? Yet this man got his miracle. Why do you think that is?
In all of eternity Jesus allowed just over three years for His in person ministry to Israel. This was the time of their visitation specifically a time for signs and wonders. Much like the wilderness was a time for pillars of fire and manna. Blessings are always two sided. the man was healed instantly , the canker of hate grew in the Pharisee and at judgement what he saw will be part of his condemnation. In Egypt the people had faith enough to follow Moses and paint their door posts. They didnt have enough faith to pack lunch for the journey. You might remember that they lived in daily sight of the supernatural, even as they clamored for the onions of Egypt. The point ?
Jesus says 
45Do not think that I will accuse you before the Father. Your accuser is Moses, in whom you have put your hope. 
46If you had believed Moses, you would believe Me, because he wrote about Me. 
47But since you do not believe what he wrote, how will you believe what I say?
They were condemned not because they denied His miracles but they failed to believe ,,, what was written.
On that both the written word and the miracles add to their judgement.
To bring it closer, we affirm the birth of Christ of a virgin, we dont have a star , or angels telling us, we look back to what is written.
But I know healings and miracles take place more in an atmosphere of faith then outside of one.
Well I know that folks who want to see healings are far more likely to offer the benefit of doubt in affirmation . Or if they decide they are under spiritual attack they will see things that confirm the negative. Its just the other side of the coin. However if you really believe
   healings and miracles take place more in an atmosphere of faith then outside of one. Then gather  your like minded friends and surround the  local  hospital and  prove it.
Be that  as it may the  purpose  of signs and wonders  was to  confirm  the  gospel that was being proclaimed. the  Gospel that  now we have in written form.