According to Bureau of transportation statistics and other sources like NATCA there are up to 33,000 US domestic flights daily. The United States of America contributes to 35% of the flights in the air everyday.
On a daily basis there are one hundred - two hundred flights and landings. There are over 70 airlines that offer flights to Rome, some are commercial, some private, and some are just cargo so prices and times vary quite a bit.
American Airlines offers almost 109 thousand seats to fly out of New York City on a daily basis. On average it appears that there are about 5 of those flights availabe from Columbus Ohio to New York City daily.
it'll take almost a day...this is assuming that you stopover in Singapore like most flights do and with a 2 hour stopover. there are no direct flights and Singapore airlines, qantas and british airways fly many flights daily via Singapore to to sydney