Here's what we know:
* Pottermore doesn't provide specific percentages or numbers for wand wood rarity. The system relies on relative terms like "common", "uncommon", and "rare".
* Cypress is listed as "rare" on Pottermore. This means it's less common than woods like Oak, Willow, or Birch, but not as rare as woods like Elder or Vine.
* Rarity is a complex factor in Pottermore. It's not just about the wood itself, but also the core material, the wandmaker, and the overall personality of the witch or wizard. This means even if a wood is considered "rare", it doesn't mean everyone with that wood will be unique or special.
Therefore, while Cypress is considered a rare wand wood on Pottermore, it doesn't mean it's incredibly uncommon. There are likely many witches and wizards who have Cypress wands, but they're not as common as those with more mainstream woods.