African trade

https://preview.redd.it/fbfmoeuco7ng1.jpg?width=2560&format=pjpg&auto=webp&s=2766b2a17fc872b738011ed63459179baa181cb1

Thanks to u/Famous_Weight6454's guide I've slightly expanded from the swahili coast to the middle east. Now, Ive controled the nile delta for about 100 years and managed to increase its market value from 2500ish to 5300, but its been stagnant for a while... And looking into other markets, Cologne sits at 11k. How could I increase my market value even further?

The whole delta is covered in cities, chili if possible, max irrigation and granaries and as many marketplaces as i could