Terrace Bankirai outside, what is the distance between the wooden planks?

We built a terrace made of Bankirai ourselves almost 10 years ago. Our spacer back then was the meter stick. So rather 2-3mm and not 7.
By the way, the terrace still looks like new. Nothing is rotting and there are no problems with water or dirt either. Painting once or twice a year is probably more important than the joint width

Nevertheless, the gap should be at least 7mm or 6% of the plank width.