Question for method

Tables 1 and 2, below, show an edited data set of some of the components of the 'organizing framework' collected at two sites in Sevilleta. Note that in each of them, 'NA' means that no data are available for that variable in the relevant year.

Table 1

Year	Precipitation/mm	Soil moisture/relative water content	Rabbit density/number of individualshectare1	Coyote density/number of individualskm2
1989	106.4	NA	NA	NA
1990	232.4	NA	NA	NA
1991	334.7	NA	NA	NA
1992	240.8	NA	0.060	0.880
1993	207.4	NA	0.272	0.702
1994	288.1	NA	0.125	0.793
1995	138.8	NA	0.246	0.575
1996	301.9	0.112	0.104	0.598
1997	325.3	0.123	0.168	0.703
1998	225.3	0.114	0.170	0.758
1999	235.7	0.094	0.138	1.065
2000	284.4	0.105	0.085	0.898
2001	214.8	0.095	0.058	0.945
2002	228.7	0.096	0.072	0.738
2003	133.2	0.100	NA	0.543
2004	301.4	0.112	NA	0.303
2005	277.4	0.110	NA	NA

I am a bit confused about part B they are asking to only use 2 variables in table one i think so i am not sure what to put in my spreadsheet ;

So i have tried doing a graph for the 1 table am i on the right track ?

n	Sample 1	Sample 2	Sample 1	Sample 2
x1	x2	Rank (R1)	Rank (R2)				x1	x2
1	301.9	0.112	19	7.5			Sum (R1 and R2) =	155	55
2	325.3	0.123	20	10			Count (n1 andn2) =	10	10
3	225.3	0.114	13	9			U values =	0	100
4	235.7	0.094	15	1
5	284.4	0.105	17	5			Medians =	256.55	0.1075
6	214.8	0.095	12	2
7	228.7	0.096	14	3			Test Statistic (U) =	0
8	133.2	0.1	11	4
9	301.4	0.112	18	7.5
10	277.4	0.11	16	6
11							Compare the test statistic (U) against the critical value for n1 and n2 degrees of freedom
12
13							For:
14							n1 =	10
15							n2 =	10
16							Critical value	23	Significant p < 0.05
17

graph