Stephen runs a pet salon. He is currently grooming $115$ dogs per week. If instead of grooming $115$ dogs, he grooms $116$ dogs, he will add $$68\mathrm{.}42$ to his costs and $$68\mathrm{.}88$ to his revenues. What will

be the effect on his profits of grooming $116$ dogs instead of $115$ dogs?

Stephen's profits will change by $$.($Enter your response rounded to two decimal places.$)$