DSCC says that the utilization rates at flexible OLED production lines have risen sharply in Q3 2020 - from around 40% to around 65% - mostly due to production for Apple's iPhones. A rise in Q3 utilization has also happened in past years, for the same reason.

TFT utilization rates by application chart (DSCC, 2019-2020)

It is also interesting to note that OLED TV utilization rates are decreasing - part of the reason is that LG's OLED fabs had limited capacity until now and operated at almost 100% rates, but as capacity increases LG is no longer capacity constrained.

Kyulux - Hyperfluoresence OLED emittersKyulux - Hyperfluoresence OLED emitters