Access to old versions of Media Encoder for AIC conversion

Hi,

I need to convert over 700 video clips which are currently rendered in AIC (Apple Intermediate Codec) into ProRes so I can work with them in Premier CC 2020. With the newer Adobe software and the newer Macs having dropped support for the codec I have an old Mac running MacOS Sierra to do all the conversion. However when I install creative cloud and try to install old versions of Media Encoder I can only access the 'latest version' 14.2 and the 'Older Version' 13.1.5 which isn't old enough to still have the codec support. How can I access an older version than this?

Thanks!