While first-year associates at the city's 20 largest law offices can expect to pull down about $71,000 a year, paychecks for the most senior associates vary by as much as 56 percent, according to a new survey. The study published in Monday's edition of the New York Law Journal found that 17 of the 20 firms pay first-year associates $70,000, $71,000 or $72,000. However, by the seventh year, base salaries vary from Cadwalader, Wickersham & Taft's $108,000 to $169,000 at Sullivan & Cromwell. George D. Reycraft, a partner at Cadwalader, told the newspaper that associates normally get a bonus at his firm. ``You see similar salaries in the early years because the firms are all competing for the same scarce resource coming out of the top law schools,'' said William C. Cobb, a Houston-based legal consultant. In its survey, the publication found average compensation for lawyers at the 20 firms are: $71,700, first year; $80,000, second year; $85,800, third year; $101,900, fourth year; $114,800, fifth year; $126,200, sixth year; and $139,000, seventh year.