High school | Undergrad. (yrs. 1-2) | Undergrad. (yrs. 3-4) | Graduate | PhD | |
28 days | $11 | $13 | $18 | $23 | $27 |
14 days | $14 | $15 | $20 | $25 | $29 |
7 days | $16 | $17 | $21 | $27 | $31 |
5 days | $18 | $19 | $23 | $29 | $35 |
3 days | $20 | $24 | $28 | $33 | $37 |
48 hours | $24 | $26 | $30 | $36 | $45 |
24 hours | $27 | $30 | $32 | $39 | $50 |
8 hours | $34 | $39 | $41 | $48 | $58 |
4 hours | $39 | $43 | $51 | $61 | $73 |