DOVER, Del. (AP) ¿ Chesapeake Utilities Corp. said Monday its first-quarter profit rose 13 percent as the utility company added customers and improved performance as its propane and natural gas subsidiaries. The Dover, Del.-based company earned $8.6 million, or $1.24 per share, up from $7.6 million, or $1.10 per share, during the same period a year prior. Revenue rose 4 percent to $104.5 million from $100.3 million. Analysts polled by Thomson Reuters expected profit of $1.16 per share. Chesapeake distributes natural gas to homes and businesses in Delaware, Maryland and Florida. Part of the revenue boost came from colder weather in the Delmarva Peninsula, which includes parts of Delaware, Maryland, and Virginia.