At 220 dirhams, proportional zakat is 5.5 dirhams because 220 ÷ 40 = 5.5.
At 230 dirhams it is 5.75; at 260 dirhams it is 6.5.
These are calculations under the view of Abu Yusuf and Muhammad. Under Abu Hanifa’s stepwise rule, 220 still entails only five dirhams.