Mexico's annual inflation rate likely rose during the first half of February as the core index remained flat, a Reuters poll predicted on Friday, boosting bets that the central bank will again opt to significantly lower borrowing costs in March. The median forecast from 11 analysts estimated that the annual headline rate likely crept up to 3.73% in the first two weeks of the month, compared to the 3.48% rate of rising consumer prices in the second half of January, when prices hit their lowest level in more than four years.