Kedah Exhibition Overprint Miniature Sheet

Kedah Postal History Exhibition was held on 20-22 March 2013 in Alor Setar, Kedah. Pos Malaysia released an overprint miniature sheet to commemorate the event.

There are two types of watermark on this overprint miniature sheet - SPM upright and SPM inverted. I am not sure which watermark type is less common. Have you got an answer for the rarity of the watermark varieties?

P/S: I was informed that the SPM inverted watermark variety is less common.