way less than 1% is my guess. There are 62 copies of Marvel 1 on the CGC census. There could be another 62 raw copies out there for the sake of this example, but highly unlikely. 880,000 copies of Marvel 1 were printed (80k OCT, 800k NOV). Even at 124 copies in proposed existence that works out to 0.00014 or .014% copies in existence. Please check my math
You can also add the extra 1 copy (I think it's only one) graded by non CGC, 3rd party graders and the % is still only marginally better than .014%