It was the size of Jupiter’s orbit, but has reduced by 15%... I’m guessing that would put it about the size of Mars’s orbit (slightly bigger).
Of course that’s just an off-the-cuff-guess.
Uh, no. Jupiter's orbit is 483,632,000 miles from the sun (on average). Mars orbit has a radius of 141,635,300 miles.
85% of 483,632,000 miles is 411,087,200 miles, hardly anywhere near the orbital radius of Mars.