A+B=60%, the whole D, that is, C: 40%, D: 60%. A and B decreased by 20% respectively, that is, D decreased by 20% as a whole, only reaching 48% of last year's total, (1-20%)*60%=48%. C Compared with last year's total, it accounts for 52% of last year's total. 0.52/0.4= 1.3, which means an increase of 30%.