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