Original sentence: Mason estimated that establishing the settlement cost him around £10,000 and would require a further £1,000 a year to maintain (today about £600,000 and £60,000 respectively) and that its annual mortality rate was significantly lower than in the rest of the town
Edited sentence: Mason estimated that establishing the settlement cost him around £10,000 and would require a further £1,000 a year to maintain (about £600,000 and £60,000 respectively as of ), and that its annual mortality rate was significantly lower than in the rest of the town