Questions about HCG Levels! HELP!

Tiana0204

• 3 weeks LMP: 5 - 50 mIU/ml
• 4 weeks LMP: 5 - 426 mIU/ml
• 5 weeks LMP: 18 - 7,340 mIU/ml
• 6 weeks LMP: 1,080 - 56,500 mIU/ml
• 7 - 8 weeks LMP: 7, 650 - 229,000 mIU/ml

My question is....  why doesn't 4 weeks start at 50, where 3 weeks ends, 5 weeks start 426, 6 weeks start at 7,340 and so on?