Federal data show tornadoes have increased across New York over the past 60 years, a state legislator said Thursday, calling for a better system to warn people to take shelter.Assemblyman Marcos Crespo, a Bronx Democrat and member of the Committee on Environmental Conservation, issued a report citing 47 tornadoes recorded from 1950 to 1970, statewide. The frequency rose through the next four decades, and there were 144 over the past 15 years. "These numbers are alarming," Crespo said. National Weather Service data also showed nine tornadoes in New York City since 2003, compared with three in the previous two decades and none before that. The 407 tornadoes since 1950 have injured 248 people, according to the report. Most occurred from May to September, with none recorded in December or February. Thursday's report acknowledged New York's history with tornadoes is much less severe than other states, but said New Yorkers appear to be increasingly facing severe weather, which also includes torrential rains, high winds, flooding and even hurricanes.