[user104658]

Ffs do people not even know how to read graph data?? This is 14/15 year old stuff? That graph shows a CLEAR upwards trend and you never take one spike in results as indicative of anything, they're called "rogue results" and this is literally GCSE/"middle school" (equivalent) stats.

Please can the people with no higher education step away from the statistics. They're making us all dumber by proximity.