A school's science department conducted an experiment measuring the growth of two types of plants over a month. The measurements, taken weekly, are summarized below:

Plant Type A: Week 1: 5 cm, Week 2: 7 cm, Week 3: 9 cm, Week 4: 12 cm.

Plant Type B: Week 1: 6 cm, Week 2: 8 cm, Week 3: 10 cm, Week 4: 11 cm.

Based on this data, which plant type showed a greater increase in growth by the end of the month?