This chart reveals a growing problem for Apple — that 'customers are getting less excited for each new generation of iPhone' (AAPL)

New iPhone models haven't sold out as quickly as they have in years past. 
Citi analysts have used search trends to surmise that "customers are getting less excited for each new generation of iPhone."Apple launched the iPhone XR at 3 A.M. in the morning on Friday, and when morning came, nearly all of the models were still in stock, according to Macworld. 
It's a change for Apple, which usually requires customers to wake up in the early morning to put in a pre-order if they want the new