In a nutshell, there's an entry of the Intel Core i5-9600K showing single-core performance of 6027 points and a multi-core score of 23472. Next we have the Intel Core i7-9700K achieving a single-core score of 6297 and a multi-core score 30152. Last we have the Intel Core i9-9900K, that one does 6248 single-core points and 33037 in the multi-core test.
The Core i9-9900K seems about 10 percent faster than the Core i7-9700K, while the Core i5-9600K is just a couple of percentage points faster than the Core i5-8600K. As always, take these scores with a grain of salt as they may not represent the performance of the final retail parts, and were captured on different test systems.